I don’t know Airtable’s official policy on the matter, but if by “app” you mean a custom block my opinion is that it probably shouldn’t have “Air” as a prefix. The reason being that it is inherently a “piece” of Airtable, and no other block has this convention. The Search block isn’t called “AirSearch,” the Whereby block isn’t called “AirWhereby,” etc.
If it is an app that exists outside of Airtable (not a block), using Air in the name is probably fine. Two of the most common ones that come to mind are “Airpress” and “On2Air”.