Preferred method for scheduling repeated execution?

`main.py` looks like it's meant to be run as a cron job or within a daemon like `supervisord`. Is that right?

Is there a preferred method for running scripts like this?

It seems like it'd be useful to use the ActivityWatcher application itself as the scheduler for scripts like this---especially if the goal is to make it easy for non-programmers to run additional Watchers as plugins. Is that something that could be in scope for the project?