If you regularly send the same message to the same person (in my case a message to my wife to tell her I'm just about to leave work each evening) then this useful little app is for you.
It stores the recurring message and the recipient and then sends the message with a single click (hence the app name).
It is a bit on the large size (5Mb) considering its limited functionality. I built this in App Inventor, and you get lots of extra stuff with that approach that I am not able to strip out. It installs to the SD card so hopefully size isn't an issue.