Short answer: they solve different problems. Swish is a mobile-first social app for finding casual open-play games and chatting with local players. Pickle IQ is what the organizer opens on the day to run balanced games, manage the queue, and show a live schedule on every player's phone.
If you're a player looking for a casual game tonight , Swish. If you're the organizer running the session — 8, 16, 40 players across a few courts — Pickle IQ. They stack well together.
Swish is a great social layer — it helps players find each other and keeps a local group talking between sessions. Pickle IQ is the operating room: once those players show up on court, it generates balanced games, rotates the queue fairly, and puts the live schedule on every phone. If you organize sessions of more than a handful of players, you'll outgrow Swish's "just show up" model quickly. Use both, in that order.