NerdzAppUpdates is a Swift package that lets an iOS app check whether the installed version is up to date with a distribution service. It supports two update flavors: hard updates (the user must update before continuing) and soft updates (the user is prompted but can skip).

The library ships two built-in version providers:

1. AppStoreVersionProvider. Uses the public iTunes lookup API to retrieve the current App Store version, then performs a semver comparison against the installed Bundle.main version. A different major triggers a hard update (for example, installed 1.0.0 vs. store 2.0.0). A different minor triggers a soft update (for example, installed 0.2.0 vs. store 0.3.0).
2. FirebaseConfigVersionProvider. Reads recommendedVersion and requiredVersion from Firebase Remote Config. Your server controls the policy, so the threshold for hard and soft updates is whatever you set in Remote Config.

You can also implement your own provider by conforming to VersionProviderType. This is the recommended path when version policy comes from your own backend.

Add the package via Swift Package Manager and depend on the master branch (or a tagged release once one is published):

.package(url: "https://github.com/nerdzlab/NerdzAppUpdates.git", branch: "master")

Requirements:

• iOS 15 or later.
• Swift 5.9 or later.
• Firebase iOS SDK 12.x (pulled transitively).

Note. Earlier versions of this project documented installation from per-provider branches (provider/appstore, provider/backend, provider/firebase). Those branches are archived and no longer maintained. Use master.

Below is a minimal UIApplicationDelegate that wires up AppStoreVersionProvider with a custom loading screen, a soft update screen, and a hard update screen.

import NerdzAppUpdates
import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?

    private lazy var versionVerifier: VersionVerifier = {
        let provider = AppStoreVersionProvider(country: .germany)

        return VersionVerifier(
            versionDataProvider: provider,
            loadingIndicationMode: .screen(LoaderScreen()),
            softUpdateMode: .screen(SoftUpdateScreen(), true),
            hardUpdateMode: .screen(HardUpdateScreen())
        )
    }()

    func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? = nil
    ) -> Bool {
        verifyVersion()
        return true
    }

    private func verifyVersion() {
        versionVerifier.verifyVersion { [weak self] result in
            guard case .failure(let error) = result else {
                return
            }
            self?.showError(error.localizedDescription)
        }
    }
}

Key points:

• VersionVerifier accepts one or more providers (variadic). Pass several if you want App Store and Remote Config results combined in a single check.
• loadingIndicationMode is optional. Use .screen(_:) for a full-screen loader (typically a copy of your launch storyboard), .custom(onStart:onStop:) to drive your own indicator, or .none.
• softUpdateMode supports .screen(_:animated:), .alert(_:), and .custom(_:).
• hardUpdateMode supports .screen(_:) and .custom(_:). The screen variant replaces the key window's root view controller, so the user cannot dismiss it without updating.

1. Keep a strong reference to the VersionVerifier instance until verifyVersion calls back. If the object is deallocated mid-check, the completion never fires.
2. When using AppStoreVersionProvider, pass the correct country in the initializer. The default country list lives in AppStoreCountry.swift.
3. The hard update flow swaps the key window's root view controller. Make sure any global state (analytics, background tasks) tolerates that.

MIT. See LICENSE.