Strobe tachometer (RPM meter)

This was exactly the app I was looking for to create a strobe light effect to set up my turntable. The free version is actually fine, but I liked it enough that I felt I should pay for it. All the other strobe apps I tried were awful in comparison.

I had a version on my iPad for years. Last update it says this app not compatible on iPad, even though it say update on App Store!, Developer got problem corrected. Great job!!

I use the free version to measure the movement of the impact head on a massage gun. Which in hertz and rpm shows very accurately. It is very easy to work with this program. Put a contrasting mark on the mechanism that you need to measure (Rotating or reciprocating). Turn on the mechanism and turn on the light on your phone, and select the numbers by which the mark becomes stationary. Definitely five stars. Do not forget to turn off the light on your phone by pressing the button in the upper right corner.