Downloaded Shot Vision today and it’s not to shabby. Used with home made set up that looks like this. Couple of misreads, but for a free app using your phone’s Microphone and Camera not bad results. Spin rate might be a little high. May even pay for the month as for just under £7 may give the gap testing and Targets a go whilst on lockdown.
Will try log on PC to see if you can edit out the misreads as when you pick it up it tends to give an extra read.