Hi Edmund, thanks for sharing all your research on this topic. Very helpful. I am using Procreate for sketching (complex work), and Notability for taking written fleeting notes. Would like to use Notability for simple sketches on the flow as well. The problem with Notability is that it is not using layers. Procreate does, but it is too complex for a simple sketch.
You mention Concepts, the app. Vector based and quite simple for simple sketching. The only problem I found that it is not possible to use different fonts in that program.
What is your experience, are there any simple sketch programs out there using layers and different fonts?
Thank!