I just released a benchmark app for iPhone and iOS called Benchmark Hunter: https://apps.apple.com/us/app/benchmark-hunter/id1591357988
I'm planning for future updates so feel free to drop me an email with feature requests, bugs, or any other concerns. bobbyschultz2@gmail.com. Full disclosure: it's not as full featured as BenchMap but I (think I) have the basics covered. You can browse benchmarks on a satellite/road map, view the mark's datasheet, and of course link to it's Geocaching.com page.
First update will be to add a topo map view. Working on that right now.
Foxtrot_xray: I've been a longtime user of BenchMap until I (hesitantly) switched to iPhone earlier this year. When I switched, I really missed BenchMap and couldn't find another benchmark app. I actually carried my old phone with me on adventures just so I would have BenchMap. I can't say enough good things about BenchMap. I am a big fan and I hope one day my app will be as full-featured on iOS as BenchMap is on Android.
Also...as my first iOS app...I now understand why developers tend to prefer Android. Working through Apple's policies, requirements, and approvals is painful and frustrating. Probably the only iOS app I'll ever build.