Whether you’re an iPhone die-hard, or you covet your Android, if you’re like us you’re always searching for fun new apps to complete your collection.  And, according to a study by the mobile analytics firm research2guidance, Smartphone owners are doing a whole lot of this—their data shows that 3.8 billion mobile apps were downloaded in just the first half of 2010—that figure exceeds the total number of downloads last year, proving that it’s an industry that’s seeing serious growth.

Along with increasing downloads, the prices of apps are also starting to increase, with the average price edging up to $3.60.  Though we’re happy to see that the mobile industry is starting to pull in more revenue—as much as $2.2 billion in the first half of the year—we still believe that some of the best things in life are free… or, relatively cheap anyway.

In honor of these cheap thrills, some of which have been long awaited by the tech community, check out these 12 apps and watch hours of your time evaporate into thin air—just kidding—but, if you have a few minutes to kill when you’re not in super-productivity mode, seriously, try the following apps we’ve selected for iPhone, and Android users to enjoy: (Note: though it was a tough choice, we decided to leave games out of this compilation, because there are simply better and more replete lists of the best gaming apps out there, like this one from Gizmodo)

1. Digg

If you haven’t heard any of the controversy, Digg is a social network that allows members to share content, and rate it with a simple thumbs up or thumbs down.  Functioning much like SEO, users are presented with the most popular content first, and links with less “diggs” or thumbs-ups secondarily.  The concept behind Digg is essentially crowd-sourced content evaluation, but it has been heavily criticized lately for allowing “power” users to dominate the charts, and thereby influence what content is presented to users.  A new version of the network may address some of these concerns, but either way, the app is guaranteed to keep you entertained. (Free)

2. Stumbleupon

Much like Digg, but less dependant on the aspect of social sharing, StumbleUpon is essentially a network designed for people who are bored and like to consume excessive amounts of content each day.  The network’s mobile app, which was released last week, is already a personal favorite of mine.  To get started, select which categories you’re interested in from a rather large list, and then start browsing through the massive amounts of content available on the site.  Once you feel comfortable, start marking favorites to have the site tailor the content more specifically to you. You can also check out your friends’ favorites and suggest content for them.  (Free)

3. Facebook

Yes, we know—Facebook is a no brainer, but the Internet’s biggest time-sucker deserves at least a mention on our list.  And, if you’re an iPhone user and it you haven’t tried ‘Places’ yet, well, now there’s a whole new way to waste your time away on Facebook! Free

4.  Netflix

If you don’t have a Netflix account, well, you should. If you do have a Netflix account then chances are you’ll love the new app.  Download it, sign-in and you can instantly watch movies and tv shows on your mobile device, or add them to your instant queue to enjoy later. (If you want to manage your delivery queue, we recommend an app called Phone Flicks). Free

5. GetGlue

Another great app for discovering your new favorites—like a hybrid of Facebook’s ‘Like’ system and Foursquare’s location based check-in network, GetGlue is a social network that allows you to connect with friends to share your common interests.  What distinguishes GetGlue from other networks of its kind is that, apart from just consuming content, you indicate your interests by liking or disliking books, movies, bands, actors, and other cultural artifacts.  With a GetGlue profile, you can also access recommendations based on what or whom you’ve demonstrated interest in, or liked. While it’s a service that many might find unnecessary, it’s fun for the culturally immersed—and besides, unnecessary is o.k when you’re killing time and having fun. Free

6. Adobe PhotoShop Express

This app is pretty self-explanatory. Don’t expect to create the same magnificent, 40-layer graphic creations that you can with the full program on your desktop, but you only get so much for free.  It’s a great app for making quick edits, like cropping, and rotating photos you snap on-the go. And, if you’re not careful, you could very well waste an hour playing around with it. Free

7. The Moron Test

Forget IQ tests, this app tells it like it is. Put your knowledge to the test with its puzzling brain-teasers, and don’t worry if you start feeling moronic—this one baffles the best of us. $0.99

8. The Dean’s List

Once you’ve graduated from the app for morons, give the Dean’s List a go—much like The Moron Test but a little spendier (higher instruction always is), it also quizzes your knowledge, but this one will really push your education to the limits—what can we say—you should have paid attention in Biology! $3.99

9. CBS Sports Pro Football

Alright, alright, for some fans, checking the scores is no waste of time, but the obsession of a true fan knows few limits—so having it all accessible at your fingertips through CBS’ app devoted to football scores and highlights may be a blessing and a curse—but either way it’s a great way to kill some time.  (The CBS Pro Football app is only available on the iPhone, but don’t worry, if you’re an Android lover you’ve got options—if Sprint is your carrier, you can download the highly rated Sprint Football Live app for free. Or, if you have a Verizon Droid, simply download Verizon’s NFL Mobile app—it’s free as well, but if you want the video highlights you’ll have to shell out $10 a month for the V-Cast service charge).  Free

10.  Pocket Universe

Though this app is most fun to use on a clear night, when you can see lots of stars, it can entertain you all hours of the day with astronomy facts, and charts of all the constellations visible at night.  Spend a little time with this app and you’ll sound like a pro next time you stare at the night sky—which is guaranteed to impress on your next date. (Again, this app is only available on the iPhone, but for a great alternative check out Google’s own Sky Map—free for download in the Android App store).  $2.99

11. Words With Friends

Okay, I’ll admit, this app is technically a game, but it’s a classic—if you love Scrabble, you’ll love Words with Friends.  Essentially, this interactive app is a souped up version of Scrabble, the board game that many of us are all too familiar with, which allows you to play against other users over your network connection.  Sure, it’s a great way to expand your vocabulary, but beware—this one is highly addictive—John Mayer even called it “the next Twitter.” Try it: Free or Buy it: $2.99

12. iFart

Simplistic? Yes. Crude? Yes. Funny? Absolutely. I don’t think this one requires much explaining—like a whoopee cushion, but with much more advanced technology.  $0.99

**Bonus**

iBeer

A great compliment to iFart—perfect your Homer Simpson impersonation with this app, which lets you pop open a virtual cold-one and guzzle it down like Homer with a Duff. Try it as a fun party trick, but we don’t recommend it for work… $2.99.

Now that we’ve shared a few of our favorite and most entertaining apps with you, stop wasting time reading this article and get back to work! But keep these in mind next time you’re stuck waiting for an appointment, on the bus, or just relaxing at home. And please share any of your favorites that didn’t make this list in the comments, below!