Bleank

There should be a prompt asking you to save before quitting.

Oh! and a feature to watch your painting being drawn from start to last save. just like a time-lapse.
I wonder if it's even possible


That is all... For now

Strange...
Normally when you leave Black Ink if you didn't save your image there is a dialog box which ask you if you want to save.
For your replay suggestion I noted it.