Edit: Whether it was the iPadOS 15.0.1 update or the accompanying reboots I don’t know, but Noir appeared on Safari on this iPad too - finally. Rating updated! Love the one developer, one (or at most a few) app shops, great attention to service usually
Read rave reviews so was eager to use on iPhone 12 and (mainly) iPad pro 12.9 2nd gen. Unfortunately, on the second it does not appear in the extension list, even with full reboot. Could be iOS 15 as that appears to be lagging in stability on the iPad Pro (2nd gen) compared to newer iDevices. Will gladly re-review when it starts to work (either by iPadOS or app fix).