Plane ride with a 15 month old?

Mikayla
We have flown several times with our daughter but this time I'll be alone with her and she'll be 15 months old. An age where she is crazy active but doesn't understand that she has to sit still and not run around.
My question is what things should I bring on the plane to help distract her? Special snacks or toys? Any advice?! I'm super nervous!! The flight is about 1 hour and then a layover and then a 3.5 hour flight.