Seems to work – Strobe tachometer (RPM meter) Review

I just used the flashlight on my iphone 6 and tried this on a machine that I had already installed a digital rpm gauge on. Set the machine at 850-852 rpms (gauge was bouncing between the two) and this app indicated 849 rpms. I then set the machine to 1360 rpms and this app indicated 1359 rpms. ?? Only downside I see is that it needs to be kinda dark and my phone’s flash had to be pretty close to spinning machinery so that I could see the line I put on it. Kinda a safety issue! Apparently you can make a remote flashlight, but I didn’t bother with that.
Review by Mr. Sleep Incorporated on Strobe tachometer (RPM meter).