Download for your device, drop in your own ROM on first launch, and log in with your account. That's it — no other installs.
iPhones can't install .ipa files directly, so you "sideload" with a free tool. Easiest is AltStore — it can even re-sign the app on-device every 7 days so it never expires.
Fastest path (AltStore):
Or Sideloadly (from a computer): grab the PokeServer.ipa, drop it into Sideloadly (sideloadly.io), enter your Apple ID, install.
Free Apple IDs cap you at 3 sideloaded apps and require a re-sign every 7 days (AltStore automates this). Nothing here needs a paid Apple developer account.
Your account is your identity — the same character follows you across every device you log in from.
Log in to see your characters and manage your account.
Your characters on the server