Toggle Settings

The Android OS provides a great deal of customization, but many of the settings are several levels deep in the desktop menu. Toggle Settings puts an on-off switch for many of the most commonly modified settings and preferences at the reach of a single button, per setting. You can turn off (or on) "Airplane Mode" (in which all internal transmitters are off) or just toggle the Bluetooth radio, Wi-Fi, data synchronization, the brightness level of the screen's backlight, the ringer, or the screen time-out timer. Preconfigured profiles let you change several settings at once.

I found this app very useful, but I wish that you could move the buttons around. Buttons appear on different tabs within the application, and I use some on the first tab and some on the second tab all the time; on both tabs, though, the app has several buttons that I never touch.