Yeah, this is really clever (sorry for my denseness in not understanding at first!) and I’m excited to hear how it works.
Note that there’s a 1% chance that when you bite your nails the next ping will take over 3.5 hours to ping. Will you remember for that long? Does it mean you need to write it down and does that defeat the point of removing the friction of tracking?
Ooh, a flip band would work well for that.
Which reminds me that another approach is to just count the times you bite your nails. With an abacus bracelet it’s pretty frictionless to keep count throughout the day and then tell Beeminder the total each night. Or use a physical button. There’s also the tally counter built in to the Beeminder Android app.