It is mostly quite primitive, but it also works amazingly well. For example ILS or VOR or ATC audio comms can all be received and read correctly using hardware

It is mostly quite primitive, but it also works amazingly well. For example ILS or VOR or ATC audio comms can all be received and read correctly using hardware built from entry level ham radio knowledge. Altimeters still require a manual input of pressure. Fuel levels can be checked with sticks. Kinda the opposite of a modern web/mobile app, complicated, massively bloated and breaks rather often :).