Plisterine is an application that will help you easily create launch agents.
What are launch agents, you ask?
With Plisterine you can create launch agents that: launch an application/script: at a specific time every day at a specific time on a specific day of the week at load or login when a change occurs in a folder (file added/deleted/moved, etc.) when a new volume or disk is mounted or that run an application: all the time (and automatically relaunch it if the application crashes) on an interval, such as every 10 seconds or every hour relaunch only after a crash (as opposed to properly quitting)