I recently came across this app during my search for a cross platform (iOS and Android) To Do app
It’s beautiful with the most delightful animations.
It’s a little simple for my needs but it may suitable to you:
It’s made by the same folks who made Forest: gamified timer
Neat! I tried WaterDo a bit this afternoon. I like the visual aesthetic quite a bit and the simple unscheduled/scheduled task panes. The price is also totally reasonable ($12 lifetime or $5/year with Forest already installed.) Unfortunately, the gestures/UX quirks that are tolerable in Forest, where you are barely interacting with your phone, are a little too much more grating in a task app that requires more frequent interaction and periods of intense input. I don’t know if it’s an inherent limitation of the game framework they’re using or just something that will be ironed out (the app is less than a year old.)
Maybe Ken Case will consider adopting bubbles as an an OF view…
Currently suffering a Heroku error. 
Oh yeah, and the git was last updated in 2017.
Might have been the inspiration, but I don’t know.