Reddit mentions of Fat Brain Toys Squigz Starter Set, 24 Piece

Others have answered the seatbelt question. I've flown with a 2.5 year old a few times--be sure to bring some small toys for him to play with. Those little hotwheel cars are a good idea, or stickers. I also bought [these] (https://www.amazon.com/Fat-Brain-Toys-Squigz-Starter/dp/B00DEBB3N0) for my (then) 2.5 year old daughter to play with during a long flight. You can stick them to the window or the seat in front of you and they are surprisingly entertaining. My daughter is now 4.5 and still plays with them now and then. I also have 9 month old and plan on bringing these with us when we fly in a few months. Also, snacks. Even if it's a short flight, snacks snacks snacks.

We do tons of toys in the bath (two of his favorites: tube https://www.amazon.com/Boon-Building-Bath-Pipes-Toy/dp/B00R0V7PUU suction things https://www.amazon.com/Fat-Brain-Toys-Squigz-Starter/dp/B00DEBB3N0). I also let him bring certain non-bath toys into the bath occasionally which gets him very excited. Color tablets are good too (https://www.amazon.com/gp/product/B004813L0S/).

M and I flew two-plus hours when he was 13.5 months and it was rough. He was newly walking so he wanted to do that, and he wasn't old enough to care about toys or videos for very long. My husband and I also flew with J and L at 13 months actual, 10 months adjusted. Also not my favorite trip. Maybe N will sleep some? I'd ask her pediatrician about Benadryl or melatonin. Things that helped a bit on both trips: lots of snacks in a big pill organizer because the doors were fun to close (Plum Organics Teensy Snacks were brand new for M so he liked those, Cheerios, goldfish crackers, Annie's graham bunnies, etc.), random things like painter's tape, Post-its, the Fat Brain Toys' Dimpland Squigz (just the bigger ones at that age), those board books with finger puppets, Matchbox cars, Sesame Street figures all provided some distraction for some period of time.