Android is now the most popular mobile OS in the world. A lot of the apps that started off being exclusive to the iPhone have come across the border and joined the green robots. So what are the best apps out there for a brand new Android device? Here's our look at the Top 10 Apps that every Android device must have. And the best alternatives in each category. Plus, for advanced users, a list of bonus apps that make your days a little bit nicer.

1 Facebook free

With 1 in 10 people in the world on Facebook, it's a safe bet that the official Facebook app for Android will be one of the first you install on your device. While it started off lacking in features, you can use pretty much every feature you expect on the web in the Facebook app. It integrates really well into the Android OS, syncing contacts and adding shortcuts throughout the system. You can check in to Facebook Places, use Facebook Chat, or just browse your news feed. It also comes with a great desktop widget which allows you to flip through the latest from your friends and share updates with one tap. It's simply the best Facebook experience on an Android device.

+ clean interface
+ official app
+ contact integration
+ chat
+ push notifications

- buggy at times
- no access to Facebook Pages
- one-way sync (contacts are lost once app is removed)

best alternative

Flow free with ads or $0.99
Not as slick, but it comes with advanced features such as HQ photos and tagging support.

2 Twitter free

Twitter has quickly evolved from being a place to share the minutiae of daily life to a real-time news service. Whether it was finding out about the Egyptian revolution or having a live discussion with the rest of the world about the Oscars, Twitter has hit the mainstream. On the Android, the official Twitter client is a mature product that is ideal for anyone who only has one account. Similar to Facebook, Twitter integrates with the address book in Android and becomes another easy destination anywhere you can share content. Again, it comes with a handy desktop widget and push notifications that you can setup for replies, direct messages, or all tweets.

+ modern interface
+ custom refresh interval
+ push notifications
+lists and suggestions.

- limited to one account
- difficult to separate important contacts from the noise.

best alternatives

Seesmic free
Combines twitter and facebook and supports multiple accounts, but fewer features all around.

Twidroyd free or $3.99
Includes unique features: multiple accounts, inline viewing of links and photos, widgets, etc.

3 SoundHound free with ads or $4.99

When Shazam launched their music recognition service over a decade ago, it was an instant success. But, it was the smartphone that really put Shazam into the hands of millions. Recently, by limiting the number of songs that you’re able to identify every month, it left the door open for competitor SoundHound to gain market share. SoundHound provides you with unlimited service and even recognizes songs when you sing or hum a tune. Shazam is now relegated to phones that don't have the luxury of having SoundHound.

+ fast results
+ unlimited tagging
+ lyrics
+ youtube links
+ one-click purchase
+ easy sharing.

- no way to share multiple tagged songs
- no offline tagging.

best alternative

Shazam free with ads or $4.99
Offline tagging, free version is limited to 5 tags a month, slower than SoundHound.

4 GoogleApps(Voice, Listen, Reader, Chrome 2 Phone) free

Google has an incredible app lineup that should be the first place to look for any Android device owner. Google Voice, whether you use it to make cheap long-distance calls, be your primary phone number, or just to be your visual voicemail service, is a must-have app. It even includes free text messaging. Google Listen is a podcast app that lets you subscribe to your favourite shows and sync it with your Google Reader account. And now that Google has a Reader app, you can browse through your customized reading list on the go and have it sync up with your browser list automatically. And the least known and most useful of the bunch is Chrome to Phone which enables you to send links, maps, and text to your Android device from any Chrome browser. Those are just some of the great apps Google has released, but you should definitely check out their full library on the Android Market.

5 Where's My Droid free with ads or $0.99

No matter how careful you are, losing your phone is always a possibility. Where's My Droid is a lightweight application that takes care of most of your recovery options. If you've lost your phone in your home, you can send a text to your phone number and it will turn your ringer on high and ring for up to 5 minutes until you can find your phone. If you don't remember where your left your phone, you can send a text with a GPS code word to your phone and Where's My Droid will use your phone's GPS signal to send you the coordinates of your phone's location. It's simple, free and works brilliantly. The developer has an option to donate to buy an ad-free version and if the app works well for you, please do that.

+ simple to use
+ unnoticeable memory usage.

- you cannot track your phone on the web
- no remote wipe

best alternatives

Plan B free
For the slacker in all of us, Plan B works after you’ve lost your phone. Installs remotely.

Lookout Mobile Securityfree
Lookout is a full suite app that backs up, secures, and can find/wipe your phone remotely.

6 SMS Backup+ free with ads or $0.99

One of the best things about Gmail on a phone is how easy it is to search for any email you've received, ever. SMS Backup+ does the same for your SMS messages and your phone calls. Once you've set up the app, it automatically backs up your SMS messages to your Gmail account, optionally giving it a label and archiving the messages for you. It also offers an option to backup your call logs to Google Calendar. If you do use the call backup, make sure you set up a separate calendar name just for the logs, otherwise you'll overwhelm yourself with the calls you make and receive. This app is one of the hidden gems that most people overlook, but is a must-have.

+ set it and forget it
+ online storage of all sms messages and call logs.

best alternative

SMS Backup and Restore free or $0.99 donation
I have this installed on my device as well as its backup & restore features are unparalleled.

7 Tango free

FaceTime making you jealous? Google Talk is perfect if you have a Honeycomb tablet, but for everyone else there’s no default video chatting app. Enter Tango, a cross-platform video call app that works quite well. If you're feeling lucky it even allows you to video chat over 3G networks, something that in a pinch could be useful (and that FaceTime cannot do yet.).

+ easy calling
+ good quality calls
+ 3G video calls
+ cross-platform.

- large app
- limited contact options

best alternatives

Skype free
Skype is cross-platform calling, but as of yet without video on mobile devices. But, with facebook integration potentially on the way, it could be the app to have.

Fring free
Fring connects to every network that allows it to connect. It's a good alternative, but not the best at anything.

8 Grocery IQ free with ads

Grocery shopping with a smartphone can be a great time-saver. Grocery IQ gives you access to shared grocery lists (between iOS devices and Android devices only,) as well as offering timely coupons in your area. The app is very well-designed and offers unique ways to add items to your list; like scanning a barcode from an item or using the predictive search.

+ great UI
+ multiple ways to input products into a list
+ coupons that stay with you.

- sharing is good, but doesn’t work well on blackberry devices
- sync is somewhat slow.

best alternative

Our Groceries free with ads or $4.99
A very good alternative. A cleaner interface with the best sync options of all apps in this category. Watch your partner shop and check off the list in almost real time.

9 Handcent SMS free with ads

It's always a little scary to replace default apps on a device with a third party offering, but Handcent SMS makes it easy. It's a customizable, light-weight, fast app that just works. If you prefer popup messages for incoming SMS messages, it gives you that option. If you like iOS style chat bubbles, you can do that. You can even change each contact's options individually. It's what Google's Messaging app should be.

+ easy to use
+ customizable
+ well-supported.

- using advanced features does take time to understand.

best alternatives

Chomp SMS/ GO SMSfree
Similar to Handcent, with very few differences. There are users who prefer one over the other.

SMS POPUPfree with ads or $1.99
If you love the default messaging app, but really like popup notifications, this app is perfect.

10 Words With Friends free with ads

Games. Everyone has Angry Birds; even Facebook is getting it soon. But, Words With Friends, while popular and made by the same company, is the game you'll never delete. Without over-complicating it, this game is basically Scrabble with your friends (or random opponents.) It's a lot of fun, works on iOS or Android and you can play when you have time. You can play up to 20 games simultaneously and notifications are built-in so you don't miss a turn.

+ fun UI with easy touch controls
+ cross-platform
+ most-popular app
+ many, many more people to play against

- dictionary is automatic (no calling your friends on made up words.)

best alternative

WordFeud free with ads or $2.99
WordFeud is the best Android-only Scrabble-esque game. But, with Words With Friends now available, there's very little reason to download this app.

BONUS: Extras to Look At

Net Counter free
Watching your data plan? Net Counter monitors it for you with a pretty good estimate of how much you’ve used.

Beluga free
Facebook just bought Beluga, a group chat app that works wonderfully.

Search Light free
Simply turns on your flash so you can see in the dark.

Gmote free or $2.99
Remote access to your music collection and ability to use your phone as a mouse/keyboard for your computer.

picplz free with ads
Instagram envy? This is Android’s equivalent. Cool photo effects and instant sharing.

Tip Me free
Going out with a group, here's an easy way to calculate tips for each person even with each person paying different amounts.

Key Ring Reward Cardsfree with ads
A database of all your rewards cards. Keep them all with you without the bulky wallet.