Components

Simple notes are widely used in writing purposes. It has great features and an easy-to-use interface.

Proposal

my suggestion for this app, the developer should add undo and redo feature.

• Undo is a command to cancel a command that has been done before.
  The Undo command is used to undo some of the last commands you performed.
• Redo is a way to repeat something that has been canceled before.
  The redo command is the reverse of the Undo command, the redo command serves to return a canceled command using the Undo command

Mockups / Examples

• Display simple notes for now
  

• If my suggestion is implemented
  

Benefits

benefit of this feature, the user can cancel the command that has been done before. And the user can also repeat something that has been canceled before.
So in conclusion Undo command is used when you want to cancel a command that you have previously done, but with the record commands are not yet save.
While the redo command is used to undo the Undo command.