After the release of the Android Nexus One phone, Google has released the software development kit that lets third-party developers write applications for the phone. Android 2.1 is a small release set out to Android powered handsets. The release includes new API alterations and bug fixes. Android 2.1 has more than a few new features in it.

The grand new features include live wallpapers, new APIs for finding out cellular signal strength and new features that an application can optionally necessitate before setting up, including a multi-touch screen. It also provides support for a camera-facing microphone and a voice recognition audio source.

It supports geolocation, web storage in Web Views and HTML5 video. It provides new methods for Android views such as opaque views and view flippers. Android 2.1 is, at present, delivering on the HTC Nexus One.

The Motorola Droid put on the market by Verizon is currently at 2.0.1 but, clients should expect an over the air update very soon. All other Android devices, about 80 percent of the market according to Google, are running version 1.6 or 1.5. Eventually 2.0.1 will leave, replaced by 2.1 just the way 2.0 was replaced by 2.0.1. If existing trends go on, it is predicted that 2.0.1/2.1 will attain a 25 percent market share by next month and 50 percent by the end of the year.

It should also be noted that all programs written using the 1.6/1.5 APIs should function on fresher devices, but you should check your applications on the entire targeted versions and screen sizes just to make certain. Programs written to involve the 2.0.1/2.1 APIs will not function on older devices.

For developers, the Android 2.1 platform is offered as a downloadable component for system development kit. The downloadable platform consists of a fully yielding Android library and system image, as well as a collection of emulator skins, sample apps, and more. It includes no external libraries.