My dad dad is into futures trading & stocks and has been using the Thinkorswim app for years but I think it's time to move to something a little less complex (not basic though) now that he is in his upper 80's. Thinkorswim has too many formatting options, clicks, etc and he frequently gets himself in bad spot and gets frustrated.

Is there anything out there that may work for him?

I don't use them, but I noticed TD Ameritrade has a free streaming channel now. Some of the shows are geared toward educating users. Brilliant move imo.

Checking back on this... we are looking for a trading platform (desktop) for my dad that is more "intermediate" as compared to ThinkorSwim

Schwab StreetSmart might fit the bill

I've never used it but isn't Robinhood ridiculously simple to trade on; I thought that was part of the issue people have with it.