I remember reading a tip more than a decade ago from a senior developer, that you should always have pen and paper next to your keyboard, to take notes, visualize problems, keep notes of where you are. Most of the thinking happens there.
When I'm working on bigger things alone, it helps me keep track or the bigger picture, how to keep separation of concern und understand where my abstractions started leaking.
Moving that pen and paper to digital unfortunately was never low-barrier for me. I thought about acquiring a reMarkable for that purpose, but it isn't perfect either.
I used excalidraw in the past, but it also does not integrate too well with my environment.
Now, with everyone being remote I would really love to have something that not only replaces my own scribbling and conceptualizing, but also serves as "whiteboard" for collaboration. I clearly clearly miss the whiteboard when discussing abstract things/ideas/problems with peers.
The app mentioned in the post seems a little abandoned unfortunately. Does someone out there use something similar?