For situations when you turn on the radio / music / movie or something else, when half enough CPU power and device flailed at maximum. One tap on the widget - and your device loses its charge longer and less heated.
It is simple and works fine like a magic)

Does not work without root.
The rate limit is configured.
Double tap opens the settings.

How to use:
1. Install the usual way.
2. Agree with root-rights to the application.
3. Add a widget to your desktop.
4. Configure the CPU frequency limit.