Android market is growing so rapidly, there are more than 40 lac applications of Android residing at Android app store that can be use to facilitate your business. On the basis of market reality, Android is still far behind from iTune application store both in term of quality and quantity. The competition is tough but both engaging to surf their customers to facilitate their businesses. Recently, I researched few applications from Android apps store that are freely available for market use. Several android applications, such as email client, SMS program, calendar, maps, browser, contacts, and others, have been developed in the Java language using the Android Software Development Kit tools and libraries. Android applications facilitate and optimize access to e-books, videos, movies, games, maps and other online resources from our home screen without having to launch a browser. With all these and other such features, Android applications occupy an important position in today’s communication in the modern world.

Microsoft has teamed up with developer seven to offer an official Hotmail app for Android, which facilitate users a simple, concise, clean interface, push notification support and enable you to manage multiple Hotmail accounts.

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.

Samsung ChatOn

ChatON is a global mobile communication service that enables you to have better relationships with your buddies and groups of buddies.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.

CamScanner is a very handy utility that lets you photograph a document – like a receipt, driver’s license, health insurance card – and save it as a PDF. From there you can crop and enhance the image and send it via SMS or email, or upload it to a cloud server. A January update adds password protection to specific documents.

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.  

BBC News App
While the BBC’s Android iPlayer app is a bit on the disappointing side, the corporation’s BBC News app is much more refined. There’s a stylish grid-based front page, plus you’re able to swipe from left to right to switch between stories in your chosen specialist category. A recent update also added a couple of Home screen widgets, too, plus the ability to submit your own news tips, as if the BBC was a small blog clamouring for content.

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’s fast and stable, with a simplicity that reminds you of the old days when using Facebook used to be bearable.

Flickr AppAs 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 hipsterise 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.

RAC Traffic
An official production of the motoring organisation, RAC Traffic is dead simple – it guesstimates your location via the mobile signal, then pops up the current traffic alerts for your area. It’s much better than having to listen to the radio for the odd update about arterial blockages.

WinampYes, 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.

ASTRO File Manager
ASTRO is nothing more than a Windows-style file explorer, but if you’re into tinkering and directly installing Android APK files yourself, it’s essential to stick something like this on your phone. It makes your phone feel like a computer, and makes you feel like you’re in charge of it. ASTRO still exists as a free ad-supported app, but you’ll have to pay for the full version without ads.

Dolphin Browser HDDolphin Browser HD is a veritable trickster of a mobile browser. You can change this Android app’s look and feel through custom themes, add capability with Add-ons, or even navigate by gesture. When you encounter a pesky mobile site, you can don a disguise—for example, you can masquerade as an iPad—to unlock the un-cropped page. Flummoxed by Flash? No more, so long as you’re running Dolphin and Android 2.2. The browser lacks a full synching service, but it does support Google Bookmarks.

Meebo IM
Meebo IM facilitate chat on multi-protocol instant-messaging networks, including AIM, MAN, Yahoo!, MySpace, Google Talk, Jabber, and ICQ. Use a Meebo account and your IM history will be saved for you to access from any computer. Price: Free.

Go SMS Pro

GO SMS Pro is a fast and convenient SMS/MMS experience. More than a stock messaging app. It features chat/list style, pop-ups, backup/restore, scheduler, encryption, many themes, and more. Solid replacement for default messaging app.

Do you love everything about your Android except its crappy battery life? JuiceDefender Ultimate is a popular app that conserves battery life by disabling the most draining components, specifically 3G/4G connectivity, when your phone is idle. You can get the free lite version, but I’d invest in the Ultimate version which lets you customize when to disable a signal; for example, if you’re listening to Pandora you wouldn’t want it to go offline simply because your phone went idle.  ($4.99)
Google Goggles
A bit of a novelty, in that Google Goggles lets you take photos and have Google analyse 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.
TangoTango Tango is the only video calling app that lets you personalize your video calls using Tango Surprises – fun animations that help you express yourself, entertain your kids, or celebrate any occasion.

Voice Recorder

A voice-recording app. Record freely or have timed recordings with pre-set limits. Works hand-in-hand with a user’s Gmail address so the MP3 file generated from the recording is emailed directly to, and stored within, the user’s Gmail account.Price: Free.

Remember The Milk

A task management app. Get alerts when tasks are due, via email, SMS, and instant messenger. The app sends alerts when users are geographically near a location where a task needs to be completed. Integrates with Gmail, Google Calendar, Twitter, and more. Price: Free.

Jorte calendar 
Jorte Calendar app displays in a monthly or weekly view. Features importing/exporting to-do data, control with Google Voice and interaction with Google Maps, and synchronizing with Google calendar. Price: Free.

A full-fledged app for Google Reader. Follow all your favorite news, sites or blogs all in one place. Discover and search for feeds. Syncs with web version, so all your reading lists are up to date. Price: Free.

Watch videos live from your PC/Mac/Linux on android. Download music from iTunes.
Emit allows you to stream videos from PC/Mac(10.6+)/Linux directly to an android device from your local wifi, 3g or external wifi. ($3.36)