This exists! You can use the mediation measurements on a Neurosky Mindwave [1] to measure when you're thinking of nothing.
I wrote an app with a friend about 10 years ago where we used the headset and the python mindwave library [2]. The app displays a longer and longer spiral on screen when you aren't thinking about anything.
I can highly recommend it. Also, it's worth using f-droid to install because otherwise you can't get the latest version.
Until I discovered termux, I would have always be on the lookout for new git client / ssh client apps. Now I have a fairly good dev env on my phone. Git and vim get me pretty far in that regard. Python and node were easy enough to set up. Recently, I set up nvim so I can use GitHub Copilot and I think it's particularly helpful on mobile.
Most of my personal projects run in containers. I know it is possible to get docker set up on Android. However, it is apparently pretty slow and it doesn't look totally straightforward to get working so I haven't tried that yet.
A few years time and hopefully I'll be running docker containers and maybe VS code will become a solid option on mobile too.
"The 2.9 billion base pairs of the haploid human genome correspond to a maximum of about 725 megabytes of data, since every base pair can be coded by 2 bits. Since individual genomes vary by less than 1% from each other, they can be losslessly compressed to roughly 4 megabytes."
I wrote an app with a friend about 10 years ago where we used the headset and the python mindwave library [2]. The app displays a longer and longer spiral on screen when you aren't thinking about anything.
[1] The headset seems to still exist in some form: https://store.neurosky.com/pages/mindwave [2] https://github.com/faturita/python-mindwave