AltStore and OTA Methods Enable iPhone IPA Installation

Installing iOS apps outside the App Store can be done with AltStore or over‑the‑air (OTA) distribution. AltStore requires the companion AltServer program on a PC or Mac, a trusted connection to the iPhone, and a valid IPA file signed with a developer or enterprise certificate. Users must enable trust for the AltStore app in iPhone settings before the sideloaded app will run.

OTA installation uses the itms-services:// protocol. A correctly signed IPA and a manifest (plist) file are hosted on an HTTPS server with proper MIME types. When a user taps the OTA link, iOS fetches the manifest, downloads the IPA, prompts for installation, and then places the app on the home screen. OTA works with Ad Hoc profiles (limited devices) or Apple Developer Enterprise Program certificates (unrestricted devices).