Twitter has launched its official application for accessing the microblogging site through smartphones running Google's Android operating system.

Twitter for Android makes it possible to share links or photos on the site by clicking the share button in an application and choosing Twitter. In addition, the smartphone app makes it possible to read tweets, the short messages Twitter users broadcast on the site to friends and followers, on a number of different places on an Android phone.

For example, the Twitter timeline can be viewed through the phone's home screen widget and a tweet location can be seen on a map. In addition, tweets can be accessed through the phone's phonebook, on Google Talk, or through any other application that uses Android's QuickContact bar.

Twitter introduced the application Friday and posted screenshots of it on the Twitter blog. The social network said Google would open-source the code used in the application in the near future, making it possible for developers to use the Twitter application programming interfaces in their Android apps.

The Twitter for Android app is available for phones running Android 2.1 or later, which would include Google's Nexus One and the new HTC Droid Incredible. However, the requirement means older phones, and even some new phones, won't be able to use the new application.

The fact that Twitter's app won't run on all Android phones is an indication of the fragmentation that could become a problem for users. Android phones each run the OS differently, whether due to screen size, keyboard configuration, or the version of Android being used.

There are currently four different versions available and it's up to the handset maker and carrier which to choose. Depending on the phone chosen, the user can get Android 1.5, 1.6, 2.0, or 2.1.

Part of the problem is due to Google releasing new core versions of the platform faster than its partners can keep up with their own tweaks and customization. Google is reportedly hoping the problem will eventually go away as the platform matures and fewer updates to the core become necessary.