I'm another one that pulled my Gemini out of a drawer where it has sat for several years, only to taken out occasionally to keep the battery exercised. I've been playing with Gemian, but in 2024 I seem to be struggling with package updates. I followed the excellent sticky at the top of this section, but find the update process is reporting missing this that and the other. Ideally I just want this device to allow me to tinker and experiment with compiling code with gcc using vim and the command line. But apt-get install build-essential just complains about not finding linked packages.
So I'm not really sure how useable the device is in 2024.
It's a great shame that the manufacturer seems to have got itself into such a pickle, seemingly moving onto the next revenue stream before satisfying those that financed the previous one(s). The device is really quite well built compared to many other devices, and when feeling the density of these newer products over the trusty old Psion Series 5mx I still have, it makes you appreciate how much the engineering has moved on. The Series 5mx feels like a plastic empty toy by comparison. Even so, with its monochrome screen and user replaceable AA batteries, it was a wonderful device though. In my opinion, no one seems to have matched it since. It's a pity these Planet devices don't look as if they have the manufacturer's support to partly fill that gap.