I had a nexus 7 as a kid, much before I had a personal laptop or even a phone. Used to utilize almost all of these features that most people seem to consider pointless. Had one of the little OTG cables so I could plug in flash storage and keyboards. I remember unzipping APKs, finding assets and trying to change them and rezipping. Only to find out they wouldn't install. Presumably failing a signature check.

Was super cool reading the OP article and finally learning how the thing actually worked with the 5th pin.