That's probably because AFAIK Apple doesn't allow process forking, making any Tor-based messenger almost impossible to run as Tor would have to run as part of the main thread.
>iOS doesn’t allow apps to fork subprocesses. While on the desktop Tor is running as a separate process, on iOS Tor is hacked to run as a thread inside the app itself. Therefore, you can’t have a system-wide Tor process like desktop and Android. If Tor is running in one app, and you open a different one, it’s not automagically going to start using Tor.
Similar? Very different. The HKmap.live app was build and marketed directly for the protests. It tracked social media and geolocated where the police and protests were happening, etc. This is a big distinction.
