Shadow provides cues about depth of the component, and expresses the degree of elevation.

It’s available from 1dp to 24dp, but buttons should have between 2dp and 12dp.

Waves Effect
Materializor uses a modified version of Waves, an external library that adds a click effect inspired in the ink effect outlined in Material Design. It can produce waves with any color.
Pulse Effect

Floating buttons can have a pulsing effect that brings attention to themselves.