Anyone used this cheapo lap timer?
 

Tempting at $40 for something basic.

have you tried harrys gps app? years ago I had the intercomp version which was not cheap. those things are a pain in the ass

I tied Harry's a few years back and could only get it to register laps about half the time. it had issues with the start/finish line. maybe it has gotten better since then.

It's dependent on your hardware, lots of people use Harry's with great success. Add a 10hz gps unit and you can get really accurate laps and lots of useful data.