Here are some instructions on how to set up Insight Timer to ring every hour

(technically, the timer is supposed to measure your meditation minutes and we will disregard this fact for now! :)

This is how the screen should look when you are finished:

Make sure you use the infinity symbol in Duration (so the timer never stops):

In “Interval Bells” - set it to 1 hour:

Touch the “Repeat” button:

And set the repeat interval to “1 hour” and be sure to set infinite repeat at the bottom: