This app was mentioned in 3 comments, with an average of 1.00 upvote
I use this on my phone ( Android )
https://play.google.com/store/apps/details?id=com.ignacemaes.bpmtap
Or you can just use this app: https://play.google.com/store/apps/details?id=com.ignacemaes.bpmtap
Or you can just use this app: https://play.google.com/store/apps/details?id=com.ignacemaes.bpmtap