Suggestion: Add undo button to posting page of esteem app

Components

I am writing this to suggest that undo button be added to the posting page of esteem app, this is because an author or user of the esteem app cannot return or undo a sentence they mistakenly deleted while typing posts in the posting page. This I noticed when using the app to type a post and mistakenly deleted a sentence or part of a sentence in that post, there is no any undo button which allow one recover such sentences or parts of posts as it can be seen on steemit website.
Proposal
To solve this problem, I am suggesting that a feature or button that allows one to undo a part of a sentence or post that has been mistakenly deleted while typing on the esteem app. This can be seen as below.

Examples

This feature is seen on the posting page of steemit website, it is also seen on various typing platforms such as Microsoft word. An evidence that it is on steemit website is below.

Benefits of implementing this suggestion
This feature will allow authors who use the esteem application to easily recover sentences or part of post that has been mistakenly deleted. It will also ensure that authors using the app are efficient in using the app thereby making them have a wonderful and better experience.
Screenshots were taken from my TecnoW2