IPA file

How it works

Rename an IPA to .zip and you can open it. Inside sits a Payload folder containing the .app bundle: the Mach-O executable built by Xcode, images and localized strings, the Info.plist that declares the bundle identifier and minimum OS version, a _CodeSignature directory, and an embedded.mobileprovision file. That last file is the provisioning profile, and it is the part that decides everything.

A provisioning profile ties three things together: an App ID, a signing certificate, and a list of entitlements such as push notifications or keychain sharing. Development and ad hoc profiles also pin an explicit list of device UDIDs, capped at 100 devices per device type per membership year. Let the certificate or the profile expire and the app stops launching on every device that has it, even though nothing about the app itself changed. Enterprise distribution certificates last three years, profiles one year, which is why a lot of internal apps quietly die on an anniversary nobody had in the calendar.

Why it matters for a fleet

The old route for internal apps was the Apple Developer Enterprise Program: 299 dollars a year, an in-house distribution certificate, and an IPA you could host on your own server. Apple tightened that door after the January 2019 episode where Facebook and Google were caught using enterprise certificates to ship research apps to consumers. Today the program is granted to organizations with at least 100 employees that can justify proprietary apps for their own staff, and applications are reviewed and refused. If you are a 60-person company with one internal app, assume you won't get in.

The clean path since 2019 is Custom Apps in Apple Business Manager. You submit the app to App Store Connect, mark it as available privately to specific organizations by their ABM token or Apple Account, and Apple hosts and signs it. No certificate to renew, no profile expiry, no hosting, and the app installs silently as a managed app through your MDM. The trade-off is real: Apple reviews it, and review takes days.

Ad hoc IPAs still have their place for a 20-device pilot. Not for a fleet of 800.

How Appaloosa handles it

Appaloosa takes internal IPA uploads with version history and per-group assignment, and it also distributes Custom Apps acquired through Apple Business Manager, so the same console serves both a pilot build and a reviewed production app. Apps install as managed apps on enrolled devices, with managed app configuration and selective wipe. See the Mobile Application Management page for the distribution model.