Hi we've made Superterm free for personal use. Feel free to try it out.

There are other free/OSS tools around, we're focusing on: long lived sessions - with notes, attention feedback, and efficient keyboard shortcuts. You don't need to be a tmux expert to use it, but there's a built-in tutor just in case you want to take it a bit further.

The mobile experience is one of the things that most other alternatives haven't touched yet - they're native apps or only run on macOS.

The PWA to me feels close to native, but has that portability.