Undo SMS sending

In Android, Contacts+ allows you to undo the sending of SMS within a specified timeframe. 

To activate this feature, open the app settings >> messaging >> select undo SMS >> select the desired timeframe (5 or 10 seconds).

Once activated, after typing a message and hitting the send button, you’ll notice an undo button next to the new message bubble. Touching it within the selected timeframe will cancel the sending of that message.