Something like https://realtrac.com/ but please keep in mind I have no experience with realtrac, it is just an example. We have a the same issue I feel your pain. I built out a spreadsheet that does a decent job if I remember to run the updates. I wind up having to do manual inventory and updates. It kinda sucks. Source: over 1 year ago

I played a PC game called "Osmos" (http://osmos-game.com/) like back in 2012 or so. It has all this electronic ambient music as the soundtrack. However, the soundtrack is not created for the game. Rather, the soundtrack is a selection of pre-existing tracks already produced by a few electronic music artists. The link above is one of my favorites. Source: almost 2 years ago

You can physically demonstrate orbit with some fabric stretched over a frame, but I really think video games are going to be your best friend here. Osmos (Free demo, $5 full) is a great starting point that uses simplified gravity in two dimensions. Orbit (Free app, $5 on Steam) is another, similar game to introduce orbit. Once you've graduated to three dimensions, Universe Sandbox ($30, $20 on GOG) will really... Source: almost 2 years ago