Canchero comes from the word cancha, which means court (sports, mainly soccer) in Spanish.
I know that it is used mainly in Argentina and in some other South American countries like Peru (where I come from).
It is a very informal way of calling someone an expert or saying that a person has a lot of experience in a certain topic/field.
However, I am not sure this is used in the same way in Spain or in other Latin American countries.
Canchero.ar is developed and it's a software to manage soccer fields and reservations, which is a pretty nice and clever way of using this word as a business IMO.