Recently HeartOnTop stopped working with Google Fit for me, presumably due to the onerous new restrictions Google placed on access to the Fit API. So I whipped up a little replacement. The main difference is HearFit requires syncing to Fit - if you don’t need that you can continue to use HoT.
Some of the advantages of HeartFit is that is doesn’t have an annoying pop-up screen when it syncs to Fit, measurement intervals smaller than 15 minutes work, and there is an optional voice coach that will announce your HR periodically.
Other options are the measurement interval which ranges from continuous to several hours, and the measurement time which should be set to the minimum time required for your watch to reach an acceptable reading.
Due to the aforementioned restrictions only a limited number of personally invited users can use the app while in the testing phase. If you want to try it please PM me your Google email address - it will go no further than your invitation. If there is sufficient interest I will submit the app to Google for review after which anyone can use it and the warnings (which you can safely ignore) will go away.
Download HeartFit 1.0.1 - heartfit1.0.1.apk - Google Drive