Android has long had a history of device fragmentation and a mix of UI implementations.  It hasn't been all that different from the Internet Explorer 6 issues web developers dealt with in the early 2000s until recently. Android device fragmentation will come to an end with the release of the newly announced version 4.0,.  A common UI will be available for phones and tablets alike.  This commonality will help ease much of the past issues from manufacturer to manufacturer.  This was a hinderance to many developers who wished to develop for multiple devices running the Android platform. Now, with the unified UI, manufacturers will be required to use the Holo theme as a base to their own themes.  The use of Holo promises to save development time by minimizing much of the UI work and allowing the customization of Holo.  Current device distribution indicates Android 2.3.3 (Gingerbread) is above 50%. Device makers will be compelled to conform to these new UI standards if they wish to connect to the Android Market.  Market access will be denied to any manufacturer who does not utilize the newly standardized Holo theme. The new UI doesn't leave out older devices.  Android's resources allow older devices to gracefully run newer apps developed for version 4.0 of the platform.  Users will welcome a unified interface.  I'm looking forward to it myself. I hope this good news has you thinking of your own future in Android development.  Before you begin, I suggest reading up a bit on development fundamentals and best practices first.  If your background isn't in mobile development, but you're still curious about the basics, read this post on Android development, and its relation to the website development process. From the Android developer blog: "It turns out that familiarity with web UI development, particularly using modern HTML5 techniques, can be a great primer for Android UI development. The Android framework and SDK have many analogues to tools and techniques in the Web repertoire of HTML, CSS, and JavaScript." A unified UI will eventually eliminate much of the mismatched menu operations and device display issues common today.  What you see will finally be what you get across devices.  This updated efficiency will speed development time from inception to release. Device fragmentation is ending soon.