That milestone was reached in the last week of 2011. And what’s really interesting is how people are finding their apps. According to new monthly data from Chomp, a search engine for mobile apps, most users aren’t looking for specific app titles, but rather features and functions — and the top feature is “free.”

In December, 82 percent of iOS users, and 86 percent of Android users, looked for apps using such common search terms as “free,” “games,” “free games,” “fun games,” “ringtones” and “shopping,” rather than searching by name.

The word “Christmas” appeared on Chomp’s list of top search terms for December, across multiple countries. The company says query volume for the word, already elevated that month, spiked an additional 300 percent immediately before the holiday, then decreased again on Dec. 25.

Chomp’s data was culled from a sample of one million search queries, across mobile platforms iOS 4.0 and higher, and Android 2.1 and higher. Chomp, which powers app searches on Verizon Android phones, just started measuring tablet-app downloads, so those apps currently account for a very small percentage of its data.

What is somewhat surprising about this report is that other data, put out last year by Latitude and MTV Networks, shows that personal recommendation is one of the biggest driving factors when it comes to app downloads, with an estimated 53 percent of mobile app users saying their friends’ suggestions are most important when it comes to finding and trying apps. If that’s the case — say, if someone asks, “What’s that iPhone app that makes photos look old and cool?” (as I was recently asked) — users wouldn’t necessarily tell their friends to search for “free photo app” but rather, look up “Instagram.”

Chomp’s technology, however, is meant to enable app search based on functionality; it also factors user recommendations and social recommendations into its algorithm. Ben Keighran, the company’s founder and CEO, says he believes Chomp’s app-recommendation engine offers more to users than just lists of top-selling apps. (For app creators, though, nabbing a top-ranking spot in app stores has been shown to boost downloads significantly, as evidenced by RunKeeper’s 637 percent increase in average daily downloads after it became a featured app in the Android store.)

Chomp’s own list of top apps for iOS devices in December included WhatsApp Messenger, JunoWallet GiftCards, Pandora, and Adobe Photoshop Express; the top Android downloads for December were Angry Birds Rio, eBay, Google+ and Google Sky Map. GT Racing: Motor Academy Free+ was at the top of Chomp’s international download charts.

Another interesting nugget from the monthly report: While paid-app downloads on Android showed no change, paid-app downloads for iOS jumped to 30 percent of all app downloads, for the first time ever. The jump was concentrated at the 99-cent price point, which increased from 15.9 percent to 17.8 percent of all apps.

But despite the fact that some customers were dismayed, Uber isn’t throwing in the towel on dynamic pricing. In fact, the company, which is usually very transparent about its surge pricing plans, is considering whether to raise fares regularly on weekends.

Could this be a Netflix-like moment for small start-up Uber, just as it’s trying to grow?

You’re probably thinking, and rightly so, that Netflix and Uber are two very different companies: Netflix is a 14-year-old public company that faces tough competition in a growing premium video-streaming market; as of the quarter ending Sept. 30, it had around 24 million subscribers. Uber is a 1-and-a-half-year-old start-up using a mobile phone application to create a marketplace that connects consumers with a limited number of town-car drivers. Netflix is available in the U.S., Canada and 43 countries in Latin America and the Caribbean; Uber currently operates in six U.S. cities and in Paris. Subscribers pay a monthly fee to Netflix; Uber users pay per ride.

But Netflix provides a recent example of price adjustments that resulted in negative consumer reaction, to put it mildly. The company said last July that it was eliminating the option to combine DVD and streaming video services, and in doing so, hiked the price by 60 percent for consumers who wanted both options. Netflix’s stock plunged; the company later cut its guidance by one million subscribers, and eventually reversed its plans to offer a DVD-only service.

As Uber has explained a few times now, the sticker shock some customers experienced on New Year’s Eve was the result of surge pricing, which Uber has started putting into effect on nights when drivers might be busier than usual. Travis Kalanick, Uber’s founder and CEO, has pointed out that if Uber doesn’t make it worth its drivers’ while to be on the platform, there won’t be any drivers available.

When it comes to tech products and services, users often don’t react well to change — at first. Professionals and consumers alike become accustomed to a product, and some initially see change as disruptive to their productivity or proficiency in that tool. There’s also often a backlash when the change results in a threat — real or perceived — to privacy, as we’ve seen with reactions to Facebook’s ever-evolving settings.

But when the change ultimately costs users or subscribers something they can peg a dollar amount to — such as the Netflix price change, or as with last week’s Verizon Wireless convenience fee — the options being weighed become that much clearer for the consumer.

In other words: Should I stay, or should I go now?

Uber does not have to worry about shareholders, or FCC scrutiny. The number of complaints logged — 97 disgruntled users and 15 whose Uber apps on their smartphones might not have been working correctly — was a small percentage of the thousands of Uber rides that were booked on New Year’s Eve. It could be said that this is more of an Airbnb moment than a Netflix moment for Uber: A case of a small start-up needing to do a little damage control.

From a business perspective, Kalanick says, New Year’s Eve was still a success. Early-stage Uber investor Jason Calacanis tweeted that he “loves” Uber’s surge pricing, as it ensures availability. (Calacanis did not immediately respond to AllThingsD’s request for comment on his tweet.)

Love uber’s surge pricing as it helps drivers & ensures availability. 5x 3 days a year is ok by me. #angelinvestment http://t.co/v2XuLT80

January 1, 2012 5:44 pm via Tweet ButtonReplyRetweetFavorite

@Jason

Jason Calacanis

Another regular Uber user, SproutSocial CEO Justyn Howard, said he used Uber on New Year’s Eve, and noted that his car ride didn’t seem any different than usual. He said he believes Uber is especially good with data-driven strategy, and that supply-and-demand management will become easier for Uber over time. “Overall, I expect the feedback and data gathered from NYE will be put to good use,” Howard said.

Uber is currently refunding some unhappy customers, on a case-by-case basis.

But for Uber, and many other start-up companies, reaching the average consumer will be critical if it wants to grow into a bigger company. By working with town-car companies and not taxis — as some other app platforms do — and charging a $7 to $8 base fare for rides, Uber is already a company that delivers a premium service that not everyone can afford.

If Uber institutes dynamic pricing on regular weekend nights, the company could solve the problem of ensuring there are enough drivers willing to opt in to Uber’s app platform, but at the risk of losing out on customers that aren’t willing to pay two times or more the standard fare.

The tech-savvy crowd, after the initial sticker shock, might accept this.

The “normals,” however, will likely stand outside a little longer hailing taxi cabs — or find other means of getting around town.

(Image courtesy of Flickr/McSmith86)

The drop-off in players affected almost all developers, but did not hit all titles equally.

For example, Electronic Arts saw 1.2 million fewer monthly users over the past week for its top title The Sims Social; Zynga’s Empire & Allies game lost one million monthly users, and its newest game, CastleVille, lost 900,000, according to AppData, which publishes such information.

On the flip side, many of the games that performed well were old favorites; these logically would have longer-term, more-committed players, who would make a point of returning during the holidays to take advantage of seasonal promotions.

The games that benefited from the holidays include Zynga’s Words With Friends and FarmVille, which gained 1.3 million and 800,000 monthly active users, respectively, according to Inside Social Games. Other gainers rounding out the Top 5 were Tetris Online’s Tetris Battle; Wooga’s kingdom-building game, Magic Land; and Men vs. Women, a role-playing game by Social Point.

Still, the general direction for the week was heading down.

That contrasts with other game platforms, such as consoles, PCs and mobile, which largely benefit from the holidays and from more free time in general.

Console games often skyrocket in popularity as kids and adults unwrap new titles for Nintendo, Xbox or PlayStation on Christmas morning.

PC gaming also typically surges during the season. EA timed the launch of Star Wars: The Old Republic ahead of the holidays, in hopes of drawing new players who would be sold on sticking around for months, after spending time on the game during their time off.

But perhaps the biggest competitor came from mobile, which benefited from breaking records for the number of new Android and iOS devices that were gifted during the holidays. Flurry reported that more than one billion apps were downloaded worldwide during the last seven days of 2011, breaking the all-time weekly record. Games are often one of the most-downloaded categories of apps.

So the more important question to ask is, why would Facebook be an exception, if other platforms performed well?

Clearly, all of the platforms are competing for a limited number of minutes in the day, and so are other forms of media, like the Internet, TV and the movies. But when it comes to Facebook, a larger driver may be the environment — after all, it’s no big secret that a lot of social networking and social gaming is done in the workplace.

In a study conducted last summer, advertising agency Saatchi & Saatchi found that 47 percent of respondents said they play social games at work during a typical day, and that 28 percent play for at least 30 minutes. Without that dedicated time in front of the computer every day, people may have had the opportunity to be more obsessed with other screens, such as phones or TVs.

Another potential reason that Facebook and social games did not see a lift from the holidays is because they have not yet figured out how to capitalize on the Christmas economy.

For years, console games have been timed with the end of the year, so they could be wrapped up and placed under the tree. More recently, smartphones and gift cards for music and apps have helped mobile prosper. Perhaps there wasn’t enough hype and promotion for social games to compete for people’s dollars.

Regardless of the reasons, the drop may ultimately be a small a blip on the radar screen for most game developers, who also see several spikes in activity during the year.

The bigger impact may be felt at Facebook, which takes a 30 percent cut of all virtual goods sold inside social games, and would feel the cumulative impact across all of the games.

Complaints arose on Twitter about the high price of Uber car rides due to so-called surge prices that were put into effect across multiple cities. One user, a San Francisco-based entrepreneur named Brendan Mulligan, described in a blog post how a two-minute, half-mile Uber ride cost him $75. He also offered some tips for improving the app.

Here’s a sampling of complaints from irate Uber customers on Twitter:

Got charged $150 for 2.4 mile ride from @Uber last night.

January 1, 2012 5:08 pm via webReplyRetweetFavorite

@peternudo

Peter Nudo

While I’m glad I’m home safely, the $107 charge for my @Uber to drive 1.5 miles last night seems insanely excessive. :(

January 1, 2012 9:46 am via Tweetbot for iPhoneReplyRetweetFavorite

@Aubs

Aubrey Sabala

A total of 97 complaints have been logged since Saturday night about surge pricing, Uber says. That does not include the 15 users the company believes may not have gotten the surge-pricing notifications through their apps when requesting cars. The company declined to say exactly how many customers requested cars via Uber on Saturday night, but founder and CEO Travis Kalanick says the total number of rides was in the five figures. Overall, he says, the evening was a success despite the complaints.

The company is reversing charges for some unhappy customers on a “case by case basis,” Kalanick says.

Uber, which launched in 2010, currently dispatches car services in seven cities, including San Francisco, New York, Washington, D.C. and Paris.

Uber doesn’t dispatch its own cars, but acts as a marketplace through which users can connect with drivers. Kalanick says the surge pricing is to ensure there are drivers available for Uber customers, since those drivers could theoretically make money elsewhere during holidays and other high-demand days.

Since Uber doesn’t dispatch taxi cabs, rates are generally higher than regular cab rides to begin with. Users get a direct-dial option for calling the driver as he or she approaches them, and the cars that arrive are usually high-end town cars. Uber rides also include a base fare of between $7 and $8 depending on the city, and the tip is automatically factored into the final price per ride.

The company has been known to put surge pricing into effect on nights when it anticipates demand to outpace the supply of car services available. The company did this on New Year’s Eve last year, and also on Halloween. When prices are about to surge, Uber sends a mass email out to its users, puts up a blog post detailing the pricing changes, and, barring technical issues, users should also get notifications through the app during times that surge pricing is in effect.

Dynamic pricing — especially when it comes to the travel industry — is not a new concept. Kalanick says Uber faces a unique challenge when it comes to changing expectations that come with decades of fixed pricing in car transportation.

“If you look at a club that charges a $20 cover on a normal night and then charges $100 on New Year’s Eve — that’s just what happens,” he told me. “But with Uber, we understand there are some people who feel the pain of that transition and we take some responsibility for making it as smooth a transition as possible.”

He said the company will still put variable pricing into effect during holidays in the future, and is currently considering whether to do the same during weekend nights.

Now — whether you can’t make it to Times Square or just don’t want to — there’s an app for that.

(Obviously!)

First introduced last year, the Times Square Official New Year’s Eve Ball App — 2012 shows a live stream of the Times Square Ball atop One Times Square, as well as video content leading up to and during the event. I’m told there will also be a live stream of Lady Gaga flicking the switch with Mayor Mike Bloomberg, to get the ball rolling, literally, at 11:59 pm ET.

With the app, users can share photos of themselves via Facebook and Twitter. They can also vote on photos — the photos with the most “likes” will be showcased on the giant Toshiba sign in Times Square that night (so if you’re at home partying in your pajamas and snapping self-portraits, you might want to think twice before sending your photos through the app).

The free app runs on iOS and Android devices, and was created by the Times Square Alliance and Countdown Entertainment, along with Toshiba and Livestream. And because few things are ever truly free, ads will run at the bottom of the app interface.

Last year’s inaugural Times Square New Year’s Eve app was downloaded 174,000 times by users in 163 countries, during a two-week period. An estimated one billion people worldwide watch the ball drop on television each year.

And 30,000 New Year’s Eve kiss photos were sent through last year’s version of the app.

Unless you’re certain you’ll want to use it again a year from now, this one can go on the short-shelf-life list of phone apps. Meanwhile, there are a few other apps you might check out for New Year’s Eve, to ensure the evening goes off without a hitch.

Like Uber, the free iPhone and Android app for calling a car service when all of the taxi cabs are taken. Uber is currently only available in seven cities, including San Francisco, Boston, New York, Seattle and Paris, and the company also sometimes adjusts pricing for holidays, like it did on Halloween this year. Uber has not yet responded to an inquiry about whether prices will go up on New Year’s Eve.

You might also want to check out an app that tempers your holiday wild side, such as the Webroot Sobriety Test app. Or an app that tests your cognitive abilities before you drunk-text, like the $.99 Textalyzer.

Or, for all those good intentions, how about an app not just for making resolutions, but for keeping them, like All My New Year Resolutions?

Public records now show the buyer was Google.

So yes, indeed, there is a body of social search intellectual property — around things like user-driven ranking of Web pages and a distributed file system — that three companies have the rights to use: Google, Facebook and the virtually unknown start-up Jildy.

Last week Jildy released its very first product: An iPhone app for clustering and sorting Facebook friends and status updates.

It’s kind of similar to Katango, a friend-sorting app that Google recently bought for an undisclosed sum.

The Jildy interface is rudimentary and so far only includes Facebook data, but it already provides some interesting tools to those who want to slice and dice their social streams.

Jildy gives users tools to monitor four types of lists:

1. keyword-based searches of their friends’ status messages that they can set up manually
2. algorithmically created lists of friends who are friends with each other (this is like what Katango did, but Jildy users can both read and write to the lists of people)
3. demographically created lists, like male friends and female friends, or San Francisco friends and New York friends
4. any lists that users have already created on Facebook

Then, Jildy tries to find out the top five to seven people or topics within each of those lists, so a user can quickly dive in and see what’s happened recently.

In the next couple of weeks, Jildy plans to add notifications. So for instance, said Jildy’s Mark Drummond (the co-founder and former CEO of Wowd), a user could be alerted every time a friend mentions a term like “skiing,” “snowboarding” or “Tahoe,” the better to facilitate serendipitous meet-ups on the slopes.

Other upcoming additions should include Twitter and LinkedIn data. Drummond said he also thinks it’s important to help users edit their friend lists to stay updated as social circles change.

On a larger note, the patent wars that plague the mobile device industry haven’t crept into social networking yet, aside from a few defensive buys throughout the years, like the Friendster portfolio (now owned by Facebook) and the Six Degrees patent (bought by LinkedIn’s Reid Hoffman and Zynga’s Mark Pincus, when Pincus was at Tribe.net).

But all the interest in the Wowd patent portfolio — which, to be clear, has not yet been used to build a successful social search product — shows that giants like Facebook and Google are attentively shoring up access to intellectual property in case social patent wars do break out.

It’s kind of ironic (and maybe even a good thing, if you don’t like software patents) that the two rivals have rights to use the very same technology from the same defunct start-up.

Palo Alto, Calif.-based Jildy has seven employees and $650,000 from Draper Fisher Jurvetson and KPG Ventures. To be specific, it has non-exclusive licenses to three awarded patents and six patent applications from Wowd, and owns three more Wowd patents. Drummond said Wowd is in the process of becoming a liquidating trust.

Photo of Mark Drummond by James Duncan Davidson for the Web 2.0 Summit 2009, where Wowd was first announced.

Apple’s App Store is on pace to exceed 10 billion downloads this year alone, which is twice the number it recorded over the three previous years combined.

The Android Market is also setting records. Over the past seven months, it has achieved more than 7 billion downloads, which more than triples its life-to-date downloads of 3 billion reached in May 2011.

At those rates, both operating systems are generating roughly one billion downloads a month, or the equivalent of 33 million a day.

The data was reported by Flurry Analytics, which creates tools that thousands of developers use to track usage of their mobile applications.

Christmas Day was one of the big catalysts for achieving huge end-of-the-year records.

Flurry found that application downloads more than doubled on Christmas compared to the average number of downloads occurring during the first 20 days of December.

On Dec. 25, it registered 242 million app downloads, jumping more than 125 percent over an average day.

In addition, because of its insight into application usage, Flurry is also able to see the number of new devices activated. Phones and tablets are always a hot Christmas item and this year was no exception.

On the average day in December, 1.5 million phones were activated, but on Christmas, 6.8 million were activated, representing a 353 percent spike. Last year, Christmas held the previous single-day record with 2.8 million device activations.