Surprised to see no mention of https://en.wikipedia.org/wiki/Game.com a terrible portable handheld that offered a 14.4 kbit/s modem cartridge.
Even if you got the extra modem gear, tho, the browser was text-only. I doubt many kids got it; I did not.
It was ambitious of Tiger (a movie-tie-in LCD game company) to try to rival the big dogs, and it makes sense but is a shame it couldn't. I'm sure there's a lesson in there somewhere.