I know apps like this already exist, but I’d make one that sends you a single positive affirmation once a day as a notification.
Nothing else.
No streaks, no subscriptions, no journaling, no extra features.
That’s all it does.
darth-pixit
Mine was an app that runs in the background and auto copies on select - ended up building it over a couple of weekends - pluks.app if you want to try it.
John_Kwick
Like a variation of some game....pong with powers and such. Or 3d tic tac toe, or or 3d connect 4. Something that start simple and by the time I know it, I am deep into it
ggm
Website implementing a couple of the classic decision support linear programming models. Not 20, and not 1. Maybe 2 or 3, with low enough barrier to enter somebody can do a "what if" over 3 or 4 unrelated criteria which need to arrive at a unified choice.