The Android versions are designed for and tested on the Motorola Droid/Milestone and Xoom, but should work on devices with similar specs. Actual speed depends on a combination of CPU clock speed and the how fast textures upload to the device's GPU. To use multi-touch, your device's screen needs to support it and be running at least Android 2.1, though the apps only require Android 1.6.
For best performance, Turn on "Direct Texture" in the options if supported by your device (Don't use on the Xoom). In case of video issues, leave it off.
The configuration files are located in the app install directory, to reset your configuration in case of issues, go to Settings->Applications->Manage Applications, select the app and select Clear Data. This only clears configuration data, all saves are retained.