Friend of mine wrote this app[0]. It’s iOS-only (I’m not the target demographic, myself, but he works for a company that serves bikers, and is very much a fitness chap). It’s quite mature, and well-maintained. Personally, I know him as an outstanding engineer, so I’m sure it’s well-written. It’s been a labor of love for him, for over a decade.

[0] https://apps.apple.com/app/id605127860