Talkback Gestures on Android
Screen reader shortcuts > Talkback
Talkback is a screen reader for Android devices.
Also available in a single-page printer-friendly PDF version.
Also available in a PDF with images depicting the gesture shortcuts.
Note:
Talkback works best with Chrome, and also works well with Firefox. If you try to use it with any other browser, it may work for some things, but not as consistently.