Clockify is an app that allows you to set a timer that plays music after it's up. Most of the time I break my work into different sprints, and having music played at once after each sprint finishes boosts my motivation to keep doing the work. The same approach might also work for you, so don't hesitate to try Clockify!
The setup and manual documents are located in the "documentation" folder.
In this version I have implemented the main functionality, which includes setting a timer up, authentication, and choosing songs to play.
Coming soon: "Chart" page, "About" page, "Marketplace" page, functionality to refresh the access token.
Don't forget to check the screenshots!