FlightConnections

Seems to provide similar information as https://aviability.com/ although with a slicker interface and monetisation.

It's a great site, I use it all the time to scope out possible routes and connections. Mostly just searching for a city/airport and seeing what all the direct flights are. I'm fortunate to live by a major hub so I hate having to make connections :P

I have never used the premium options.

Minus points for redirect trapping.

Two minutes in and I have:

   1. Figured out how to create circles -- sort of, by deleting and allowing it to recreate them
   2. Figured out how to set the diameter of circles by dragging the point on their circumference -- choosing a radius in the search box doesn't seem to work
   3. Figured out that small circles aren't possible -- both in NYC and SF I had to drag the center of the circle out into the ocean to get a circle limited to the airports I was interested in
   4. Seen the sign-in/ads dialog twice
   5. Gave up on actually trying it out.

Might be good for the home page to say something about what it is, beyond just showing a map with dots.

Cool kids who are in the know are generally a smaller population than one might hope when launching a site.

Hmm, so kind of like Rome2Rio but restricted to air travel, instead of all travel.

https://www.rome2rio.com/

This is an awesome site in that it can identify whether a nonstop flight is available between two small cities or what directly flights there are to a country like China which post pandemic has very few direct flights.