Play a clone of Tetris
Tetris has suggested efficacy in attenuating development or severity of trauma and it seems to have a beneficial ongoing cognitive effect also.
Don’t get Tetris™️, get a good paid version that lets you buy it and doesn’t show ads or track you after buying.
I use my phone like a sensor for accelerometry when I’m curious about the forces acting on me. Or iI use it as a spectrograph.