Idea for Overdraft Protection

Having gross rules for overdraft protection isn't acceptable in this day and age. At my current bank, I can either opt-in or opt-out.

However, not all transactions are the same. For emergency purchases, I'm okay with the $20 penalty. Yet, at the same time, I don't want a $22.26 cup of coffee.

These days, I can make bank transfers from my phone in real time.

How about the capability to approve / decline overdraft transactions in real time on your phone?

I understand that overdraft fees are a way for banks to make money, but with so many people opting out, it might be a nice bump.