FlixSeats
I don't want to pay extra to choose a seat on FlixBus, obviously. So I get assigned a random one. Then I get on the bus and there are whole rows empty up front. Why would I sit at the back next to the toilet, next to someone, when there are literally four empty seats in a row? I'm not sitting inside of the toilet.
So I made FlixSeats to see where it's empty. Five minutes, two prompts maybe. It's useful. Try it out.
FlixBus has a seat-map endpoint on shop.flixbus.ca: POST /ancillaries/proxy/seat-map/by-ride/{rideId}. I take the ride and stop IDs from a trip search and send them to that endpoint. No account or authentication token. It returns the seat layout and which seats are available, so I draw them. The data is already there. Let's use it.
This checks availability; it doesn't reserve a seat.