Polarr allows infinite undos and redoes to any step of your edits. This includes everything from adding a new brush stroke, a text movement, a new crop ratio, and all global and local adjustments.
This feature allows you to edit without fear of making any permanent mistakes to your photo. Try something new and see how it looks. Don't like it? Just go back a step or multiple steps to any point in time you want.
You're basically a time wizard with this feature.