I just started using Cyclemeter and have been pleased. It paired easily with my Wahoo Blue SC Speed and Cadence sensor and it gets HR off of my Apple Watch. It appeared to be the only app that could do both but you do have to pay the $9.99 per year for pairing, Apple Watch functionality and Strava support among many other things. One of the neat things is that it will download an app on your Apple Watch where you can get additional screens of data. The downside is that it does a bit too much out of the box and it the app crashed 100 miles into a 110 mile bike so I lost the last 10 grueling miles! I’ll be customizing it as I play with so I’m not worried at this point.