I released the source code of the scheduler feature (web app)
You can test it at:
Please, have a look at the readme, it's still a work in progress.
PS: Nothing is stored locally on the server and no third services are used for hosting data.
@fedilab It is a self hostable message scheduler for Mastodon/Pleroma? That is interesting. I have never dabbled with scheduled toots, I always assumed that they are essentially useless unless you are marketing something