Wow. This is a very nice initiative. I'm sure it would have aid my trading journey a lot more if I learnt of this some years ago. I believe it is especially good for newbies who are just starting out in trading.
I'd have suggested you add the stop loss and take profit features but I realized someone already mentioned it which is good by the way. Having Stop Loss is especially beneficial for newbies who don't have a risk management plan.
I know you've gotten more ideas on how to improve the app by the several responses given already in the thread.
I doff my hat to you on this great idea.