I also recently acquired some free e-waste android 6 devices (like a galaxy note 4 pad and a moto 4 phone). Using some vibe coding I was able to setup a dockerized build system for java/kotlin apps and managed to make a number of custom applications for the devices like turning them into timelapse+mjpeg streaming cameras (or irc client, or ice thickness estimation from chirped sounds+dsp). Since they're ewaste I don't mind if they get destroyed or lost.