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Siren – Notify users when a new version of your app is available and prompt them to upgrade.

CocoaPods  Carthage Compatible SwiftPM Compatible CocoaPods CocoaPods


Siren checks a user’s currently installed version of your iOS app against the version that is currently available in the App Store.

If a new version is available, an alert can be presented to the user informing them of the newer version, and giving them the option to update the application. Alternatively, Siren can notify your app programmatically, enabling you to inform the user through alternative means, such as a custom interface.

  • Siren is built to work with the Semantic Versioning system.
    • Semantic Versioning is a three number versioning system (e.g., 1.0.0)
    • Siren also supports two-number versioning (e.g., 1.0) and four-number versioning (e.g.,
  • Siren is actively maintained by Arthur Sabintsev and Aaron Brager

README Translations


  • Siren is a Swift language port of Harpy, an Objective-C library that achieves the same functionality.
  • Siren and Harpy are maintained by the same developers.
  • This library was the inspiration for Egghead Games’ Siren library, which achieves the same functionality with the Google Play store on the Android platform.
  • This library was the inspiration for Gant Laborde’s Siren library, which achieves the same functionality for React Native projects (iOS/Android).


  •  CocoaPods Support
  •  Carthage Support
  •  Swift Package Manager Support
  •  Localized for 30+ languages (See Localization)
  •  Pre-Update Device Compatibility Check (See Device Compatibility)
  •  Three types of alerts (see Screenshots)
  •  Optional delegate methods (see Optional Delegate)
  •  Unit Tests!


  • The left picture forces the user to update the app.
  • The center picture gives the user the option to update the app.
  • The right picture gives the user the option to skip the current update.
  • These options are controlled by the SirenAlertType enum.


Installation Instructions


For Swift 3 support:

pod 'Siren'

For Swift 2.3 support:

pod 'Siren', :git => 'https://github.com/ArtSabintsev/Siren.git', :branch => 'swift2.3'

For Swift 2.2 support:

pod 'Siren', '0.9.5'


For Swift 3 support:

github "ArtSabintsev/Siren"

For Swift 2.3 support:

github "ArtSabintsev/Siren" "swift2.3"

Swift Package Manager

.Package(url: "https://github.com/ArtSabintsev/Siren.git", majorVersion: 1)


Here’s some commented sample code. Adapt this to meet your app’s needs. For a full list of optional settings/preferences, please refer to https://github.com/ArtSabintsev/Siren/blob/master/Sample%20App/Sample%20App/AppDelegate.swift in the Sample Project.

Full documentation can be found at http://sabintsev.com/Siren.

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    /* Siren code should go below window?.makeKeyAndVisible() */

    // Siren is a singleton
    let siren = Siren.shared

    // Optional: Defaults to .Option
    siren.alertType = <#SirenAlertType_Enum_Value#>

        Replace .Immediately with .Daily or .Weekly to specify a maximum daily or weekly frequency for version
    siren.checkVersion(checkType: .immediately)

    return true

func applicationDidBecomeActive(application: UIApplication) {
        Perform daily (.Daily) or weekly (.Weekly) checks for new version of your app.
        Useful if user returns to your app from the background after extended period of time.
         Place in applicationDidBecomeActive(_:).   */

    Siren.shared.checkVersion(checkType: .daily)

func applicationWillEnterForeground(application: UIApplication) {
        Useful if user returns to your app from the background after being sent to the
        App Store, but doesn't update their app before coming back to your app.

       ONLY USE WITH SirenAlertType.Force

    Siren.shared.checkVersion(checkType: .immediately)

And you’re all set!

Prompting for Updates without Alerts

Some developers may want to display a less obtrusive custom interface, like a banner or small icon. To accomplish this, you can disable alert presentation by doing the following:

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    siren.delegate = self
    siren.alertType = .None

extension AppDelegate: SirenDelegate {
    // Returns a localized message to this delegate method upon performing a successful version check
    func sirenDidDetectNewVersionWithoutAlert(message: String) {

Siren will call the sirenDidDetectNewVersionWithoutAlert(message: String) delegate method, passing a localized, suggested update string suitable for display. Implement this method to display your own messaging, optionally using message.

Differentiated Alerts for Revision, Patch, Minor, and Major Updates

If you would like to set a different type of alert for revision, patch, minor, and/or major updates, simply add one or all of the following optional lines to your setup before calling the checkVersion() method:

    /* Siren defaults to SirenAlertType.Option for all updates */
    siren.shared.revisionUpdateAlertType = <#SirenAlertType_Enum_Value#>
    siren.shared.patchUpdateAlertType = <#SirenAlertType_Enum_Value#>
    siren.shared.minorUpdateAlertType = <#SirenAlertType_Enum_Value#>
    siren.shared.majorUpdateAlertType = <#SirenAlertType_Enum_Value#>

Optional Delegate and Delegate Methods

Six delegate methods allow you to handle or track the user’s behavior. Each method has a default, empty implementation, effectively making each of these methods optional.

public protocol SirenDelegate: class {
    func sirenDidShowUpdateDialog(alertType: SirenAlertType)   // User presented with update dialog
    func sirenUserDidLaunchAppStore()                          // User did click on button that launched App Store.app
    func sirenUserDidSkipVersion()                             // User did click on button that skips version update
    func sirenUserDidCancel()                                  // User did click on button that cancels update dialog
    func sirenDidFailVersionCheck(error: NSError)              // Siren failed to perform version check (may return system-level error)
    func sirenDidDetectNewVersionWithoutAlert(message: String) // Siren performed version check and did not display alert


Siren is localized for

  • Arabic
  • Armenian
  • Basque
  • Chinese (Simplified and Traditional)
  • Danish
  • Dutch
  • English
  • Estonian
  • Finnish
  • French
  • German
  • Greek
  • Hebrew
  • Hungarian
  • Indonesian
  • Italian
  • Japanese
  • Korean
  • Latvian
  • Lithuanian
  • Malay
  • Norwegian (Bokmål)
  • Polish
  • Portuguese (Brazil and Portugal)
  • Russian
  • Serbian (Cyrillic and Latin)
  • Slovenian
  • Swedish
  • Spanish
  • Thai
  • Turkish
  • Vietnamese

You may want the update dialog to always appear in a certain language, ignoring iOS’s language setting (e.g. apps released in a specific country).

You can enable it like this:

Siren.shared.forceLanguageLocalization = SirenLanguageType.<#SirenLanguageType_Enum_Value#>

Device Compatibility

If an app update is available, Siren checks to make sure that the version of iOS on the user’s device is compatible the one that is required by the app update. For example, if a user has iOS 9 installed on their device, but the app update requires iOS 10, an alert will not be shown. This takes care of the false positive case regarding app updating.

Testing Siren

Temporarily change the version string in Xcode (within the .xcodeproj) to an older version than the one that’s currently available in the App Store. Afterwards, build and run your app, and you should see the alert.

If you currently don’t have an app in the store, change your bundleID to one that is already in the store. In the sample app packaged with this library, we use the iTunes Connect Mobile app’s bundleID: com.apple.itunesconnect.mobile.

For your convenience, you may turn on debugging statements by setting self.debugEnabled = true before calling the checkVersion() method.

App Store Submissions

The App Store reviewer will not see the alert. The version in the App Store will always be older than the version being reviewed.

Created and maintained by

Arthur Ariel Sabintsev & Aaron Brager


Source: https://github.com/ArtSabintsev/Siren

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