25 Years Ago, Apple Introduced the Newton

Einstein runs on Android, so if you have a phone with a pencil (e.g. the Note 7), you pretty much have a Newton. It still holds up; I wish my phone worked more like a Newton.

Sadly, some of the Newton's best software (e.g. Columbo's Mystery Capers) is not available in any way except for the original cartridge, so it only runs on original hardware (if you're lucky enough to get it on eBay).

Flashback! Guy in my senior class had a Newton MessagePad. He used it in school like a mini CEO. Was pretty cool hardware, even given it's limitations.