Caffeinate
Caffeinate is a drip engine for managing, creating, and performing scheduled messages sequences from your Ruby on Rails application. This was originally meant for email, but now supports anything!
Caffeinate provides a simple DSL to create scheduled sequences which can be sent by ActionMailer, or invoked by a Ruby object, without any additional configuration.
There's a cool demo app you can spin up here.
Now supports POROs!
Originally, this was meant for just email, but as of V2.3 supports plain old Ruby objects just as well. Having said, the documentation primarily revolves around using ActionMailer, but it's just as easy to plug in any Ruby class. See Using Without ActionMailer below.
Is this thing dead?
No! Not at all!
There's not a lot of activity here because it's stable and working! I am more than happy to entertain new features.