The open source nature of Google's OS means there are plenty of fantastic apps for Android to be found.

And most of the good stuff on Android is free, thanks to the work of developers who do it for love alone.

So here's our pick of the top free Android apps you should install.

You can find more great apps at Top 200 best Android apps.

Also why not check out our video of the top 10 free Android games?

1. Trailer Addict

iOS 6 users have Apple Trailers, and Android fans have Trailer Addict, a timely, high-resolution source for the latest move trailers. Trailer Addict hosts official versions of movie trailers, and unlike YouTube, you won't have to wade through idiotic user comments or wait to skip an ad before your video loads. There's just the occasional banner ad at the bottom of the screen. So while most summer blockbusters are garbage these days, you can enjoy the best part, the trailer, while on the go. TA makes a great addition to an HD screen and 4G LTE.

Trailer Addict

2. Juice Defender

With great power comes a great drain on battery life. If you've got a whopper of a handset that chews through its charge at an unreasonable rate, you can squeeze some extra percentage out of it with Juice Defender. JD is an awesome suite of active and background functionality. It includes a powerful task manager for dumping and disabling battery tasking apps, and it can be set to automatically toggle charge sucking features like 4G LTE and WiFi. If you've got an HTC One X + or One X, you need juice defender.

Juice Defender

3. Swiftkey 4.0

One of the best parts about the Android OS are third-party keyboards, and while it's hard to pick the best set of digital keys, Swiftkey is certainly in the running. It actually builds a heat map of how you type, meaning if you tend graze the right side of the A key, Swiftkey will adapt to that. It'll also read your email and Facebook posts, if you let it, in order to learn your most common phrases. That means that typing "hey man what's up?" can be reduced to five keystrokes or so.

Swiftkey

4. Screebl

Screebl is a brilliant little utility for saving battery life and killing your phone's annoying habit of dimming the screen when you're trying to read. It uses your phone's gyroscope to guess when you're actively watching the screen, and when it can go dim to save some juice. It's a shockingly good guesser, making it the perfect background app for battery fiends and avid smartphone readers. It makes a great sidekick for Instapaper!

Screebl

5. Speed Test

Whether you're looking for bragging rights with your tech buddies or you're just curious why the speed you experience varies so widely depending on where you are, Speed Test is a great way to find out what type of data speeds you're experiencing. Of course, data speeds also vary from carrier to carrier, so Speed Test is also a great way to shop for the carrier that has the best speeds in your area.

Speed Test

6. Dropbox

Available on nearly any platform currently available, from PCs and Macs, to cell phones and tablets, Dropbox provides an excellent method for backing up data to the cloud as well as accessing that data on the go. You can also set Dropbox up to automatically back up data from your phone. While Dropbox is free with 2GB of storage, users can increase their available storage by adding new devices and referring other users. Pro plans which offer significantly more storage are also available for a monthly fee.

Dropbox

7. Seesmic

There are many Twitter apps on Android - and Twitter itself shook up the scene with the launch of its own-brand app - but we're sticking with Seesmic. Offering support for multiple accounts, a home page widget showing latest tweets and an incredibly slick and professional design, it's one of the finest examples of app development out there today.

seesmic

8. Facebook for Android

Facebook for Android is lacking in features compared to Facebook itself, but a recent update added Inbox support to the Android app, finally allowing its users to communicate in almost real time. The app is fast and stable, with a simplicity that reminds you of the old days when using Facebook used to be bearable.

Facebook

9. Hotmail/Outlook

Microsoft has teamed up with developer SEVEN to offer an official Hotmail app for Android, which gives users a simple, clean interface, push notification support and even lets you manage multiple Hotmail accounts from within the app. If your email needs haven't yet been assimilated by Google, it's a useful option. It's since been rebranded as the Outlook app, in keeping with Microsoft's changes to its mail site.

Hotmail

10. Google Sky Map

A stunning app that renders Patrick Moore obsolete, by using your phone's orientation tools to give you an accurate representation of the stars and planets on your screen. Point your phone at the sky, then learn what constellations are visible and if that's a UFO or just Venus. Google Sky Map even works indoors, if you're not keen on getting cold.

Google sky map

11. SoundHound

If you're in a store shopping or happen to hear a song without the radio announcing the band, whip out the SoundHound app to figure it out for you. Or if you like, hum or sing the tune and the app should be able to recognize it.

SoundHound

12. Foursquare

The social media darling Foursquare is represented in fine form on Android, with the Google app offering easy one-click check-ins, integrated Google Maps for a seamless Google-branded experience and home page shortcut options to all your favorite places.

FourSquare

13. WordPress for Android

WordPress for Android started out as independent creation wpToGo, before WordPress decided it liked it so much it bought it up - hiring the maker to develop it in-house. It's very feature-packed, with the latest version offering full integration with other apps, letting you spin content and send it directly to the app for easy updating. It could do with more image insertion tools, though.

WordPress for Android

14. Google Goggles

A bit of a novelty, in that Google Goggles lets you take photos and have Google analyze them and come back with a search results page for what it thinks you're looking at. However, the app's main use is as a QR code reader, which lets you scan barcodes for quick access to apps and whatever data people choose to embed in the odd little data squares.

Google goggles

15. Winamp

Yes, the same Winamp from a decade ago. It's had an Android app for some time, with recent updates adding support for iTunes, Mac syncing, plenty of music streaming options, new release lists and Shoutcast integration for radio support. It's a fine, free media player.

Winamp

16. Samsung ChatOn

There are plenty of messaging tools on Android, but Samsung's beats many of them by offering multi-platform support - with clients even available for older Samsung non-smart feature phones. It could be the ideal way to keep in touch with an out of touch relative. More "with it" users will be able to use its drawing, image sharing and social networking features.

Samsung

17. Skyfire 3.0

The USP of the Skyfire browser is that it supports Flash content, popping up a little window when it detects an embedded YouTube video or something similar. The actual Flash business is handled by Skyfire's server, which does all the computery stuff, then sends the file to your handset. A bit clunky on slower Android phones, but it works like a dream on models with faster processors.Despite the arrival of Flash with Android 2.2, this is still relevant for those on phones and Android versions not able to support Adobe's Flash Player.

Skyfire

18. Swype

The odd line-drawing alternate keyboard Swype is a love-it or hate-it kind of thing, with the significant amount of re-learning required to make the most of it quite offputting to some users. But, once you're familiar with the idea, it's genius - with advanced prediction options further speeding your line-typing. Swype is not available through the Android Market - the only way to install is is via a direct download from the maker.

Swype

19. Evernote

After the Android version of Dropbox, the next best solution for keeping all your "business" in one place is Evernote - it lets you stash and sync all your text notes, voice memos and files on your phone and access them through a desktop computer.

Evernote

20. Flickr

As well as supporting Flickr uploading, this app also lets you capture photos from within the app and comes complete with a set of filters, so you can hipsterize your life with ease. It supports sharing with Twitter and Facebook as well, so your other, non-photo-nerd friends can enjoy the results of today's snapping session.

Flickr