Undo button and save
Many times I need to undo a small change and it changes in one press three movements prior.
Also I've left more than once an unfinished to continue later and when I go back the changes haven't been saved.
Also, you don't allow to zoom in the workspace, at least in an easy way that I could see. When you are trying to do a detailed work is essential, specially when working on a phone.
This are major issues that need to be fixed.