I started out adding functions that I found to be helpful in using my Droid. For example, from the first time I used my phone, I found the placement of the power button a bit awkward to press every time I wanted to wake up the phone. That was the starting point - make the phone wake up by shaking it.
I also realized that the music player was very difficult to use due to the phone being touch screen. Whenever I wanted to pause the music, for example, I had to awkwardly press the power button to wake up the phone, enter my passcode to unlock the phone, pull down the notification window shade, open the music player, and then press pause. The music widget made it a little better, but still not where I thought it needed to be. Sometimes I would listen to music at work and would get a phone call on my office line. Forget about pausing the music because the call would have gone to voicemail by the time I did that. So the Shaker app will now pause my music, as well as resume, and it will skip forward or back a song, with a simple shake of the device.
The last function I included in this release is a shaker to answer the phone when a call is coming in. I also found answering phone calls awkward to do with one hand, and it was that much worse if it were winter and I was wearing gloves.
My hope is that this app will make Android phones more usable for people out there. I'm very excited about the Android platform and equally excited to hopefully be contributing towards making it better. I will continue to add more functions to the app, so let me know if there is anything in particular you would like to see included.
Also, it is important to note that the app is still in Beta testing. I have only been able to test on the Droid so far, so it would be awesome if people can send me their feedback when using this on other devices, particularly the Nexus One and some of the newer devices coming out over the next couple of months. One thing I am curious about is the direction of the shakes detected on other devices. On the Droid, the directions were all opposite of what I expected, so I wonder how differently it will behave on other devices. If I manage to make a few bucks off this, I will invest in some developer phones and will also try to make this compatible with older versions of the OS as well. Please send me your feedback!