Say you’ve been using your Android for a while and you keep checking the Market to see if someone has finally released that app that you’ve been waiting for, but it never shows up. Out of frustration you decide that you’ll write it yourself and become rich and famous, but where to start?
First I’d recommend you pick up a copy The Back of the Napkin by Dan Roam to help you sketch out a concept of your app, its dependencies, and interconnections.
After you’ve got a good idea of what your app is (and a better picture of what it is not) it’s time to start mocking it up. I’m a firm believer in letting form follow function, but let’s face it, your app has to be intuitive and easy to use. Before you write a single line of code, might I be so bold as to recommend that you wire-frame your app’s UI? Don’t worry, you don’t have to reinvent the wheel, there are already common UI controls that you can leverage, but to help you sketch them check out Android Sketch Stencil Version 1.0 by mikec78uk. These wire-frame stencils can help speed up development of your app without bogging you down with specific UI elements.
If you are working on a development team, or outsourcing app development, these “rough sketches” can help communicate design ideas without getting lost in the minutia, or hesitating to make a change because “the design is too far along”.