A. Force close the app and restart it. Double-click the home button (or swipe up from the bottom of the screen on newer iPhones) to see all open apps, swipe up on the VPN app to close it, and then reopen it.

B. Reinstall the app. If the app still does not open, delete it from your device by pressing and holding the app icon until it wiggles, then tap the 'X' to delete. Reinstall it from the App Store.