The hardest part of any sport is finding someone to play it with.
Post the session you want — tennis, climbing, football, anything, indoors or outdoors. Someone nearby who wants the same game finds it and asks to join. You pick who plays.
What it does
You post the session you want to play: sport, when, where, your level. People nearby who want the same game find it and ask to join. You choose who plays.
Who it serves
Anyone who wants to play but has no fixed partner — the player whose usual partner bailed, the person new to a city, the weekend warrior who can't find a game.
Why it works
No algorithm guessing at chemistry. You see who's playing and you decide. Two people who both want to play is all it takes.