Link to public repository (Github, Bitbucket, etc)
https://github.com/shubshub/Save-Load-Replay-and-Rewind-for-Game-Maker

Link to documentation
https://github.com/shubshub/Save-Load-Replay-and-Rewind-for-Game-Maker/blob/master/README.md

Do you have a demo (or example) in your project?
Yes, Its just a simple SHMUP that shows Saving, Loading and Rewinding