The notes, alarms etc part sounds like PDA (Personal Digital Assistant) to me. My dad used them extensively in the 90s and I would argue that they are the true predecessor to the modern smartphone.

I also remember my dad having a GPS device without a map. You could input waypoints and record a route and that's it. I searches a bit and it looks like it was Garmin GPS 45 XL (but I might need to confirm that with him - I'm sure he has it somewhere)

There were also early examples of portable mp3 players in the late 90s. I think they were mostly held back by the storage density - the best option was the ultra small HDD (like the first iPod had in 2001). I think a portable CD player was the default back then.

So all the ingredients were there in the late 90s, just not in one device.

The most fun bit of tech history I found on the internet is this mp3 car stereo from 1999, which was running Linux. It had max capacity of 28GB for the music (2 HDDs). I don't see myself needing much more than that even now. It was quite expensive, so it didn't sell very well.

I've also read that people would drive with a PC in their trunk with some head unit, so they could listen to mp3s it in the car. It would totally be me if I were the same age as now 30 years ago.