https://en.wikipedia.org/wiki/I-mode
At 80M subscribers, it was probably the most popular way in the world to access mobile internet pre-iPhone.
I-mode also introduced the original set of emojis that are now supported everywhere.
Psion is the big one - the Organiser, Series 3 and Series 5 in particular. The latter was the genesis of Symbian, which Motorola was also a partner in.
Same for Palm - it wasn’t until the Treo series that they started trying to make inroads in the smartphone field.
I had both Palm PDAs (a V and a tungsten 3) and a psion (diamond Mako), fun times with portable computers.
This was because the acquisition of Handspring, right?
Prior efforts were menu oriented or attempts at desktop UI on a tiny screen, like WinCE.
I worked on a Linux based tablet back in '99, that had all of those flaws.
Apples biggest innovation was recognising when the hardware had caught up enough to make this attractive to normal consumers.
That's not a small thing - the entire rest of the industry tried,failed, and wrongly assumed the failure meant the concept was a dead end and mostly abandoned it, before Apple resurrected it.
I think until the iPhone most of the touchscreens were resistive and single-touch. It was multi-touch capacitive screens, alongside Jeff Han's multi-touch demo that captivated everybody's imagination.
I think the big diff was assumption of handwriting as the UI. Latter palm treo had a keyboard like blackberry, I used several generations of those before trying the HTC g1 :).