Here's a new dynamic control for Android: a Rotary Knob. It can be used to adjust a value similar to a slider, but it is circular and has a certain advantage when it comes to aesthetics.

Additionally it can be made to accept clicks, so besides working as a slider it can also function as a button. Either a momentary push button or a switch that can be toggled on or off.

Project details: http://www.pocketmagic.net/2013/11/custom-rotary-knob-control-for-android/

See the wiki on https://github.com/radhoo/android-rotaryknob-view/wiki