Fun anecdote yesterday where your app would have been useful. Lots of sub-4 year olds on an evening AUS-MDW. Various levels of crankiness even when boarding. I'm in 18C, and this really cute 2-ish year old girl comes up to me during family boarding and shows me her stuffed fish. I was hoping that one her parents would sit in my row because it would give me more shoulder room if the little girl was in the center. But they had two kids so they wanted window/middle in consecutive rows.
So the mother asks 16D if they can sit in EF, The woman replies: "only if your child is well-behaved!" The parents rightfully get miffed, and move back to the early 20s.
The woman in 16D could have used your app.