Tap the App Store icon from your iPhone's home screen, and then locate the NextCrew app. Check NextCrew's app system requirements in the "Requirements" section to verify it is compatible with your iOS version.
Tap Settings, then General and then tap About to check your iOS version. If you're using a version that is not compatible with the NextCrew app, tap Software Update and install the latest version.
Open the App Store and tap Updates to see if there are newer versions of NextCrew app.
Press the Home button twice, then tap and hold the NextCrew app until it starts to wiggle. Touch the red minus symbol to close it. Press the Home button twice, then try opening the NextCrew app again.
Press and hold the Sleep/Wake button until a red slider appears on the iPhone's screen if the NextCrew app is still not opening. Slide your finger across the slider to turn off the iPhone completely. Press and hold the Sleep/Wake button again until the Apple logo appears on the screen, then launch the NextCrew app.
Touch and hold the NextCrew app until it starts to wiggle, and then tap the X icon in the corner if you're still experiencing difficulty. Tap Delete to remove the app completely and all its data from your IPhone.
Tap the App Store from the home screen and locate the NextCrew app to reinstall. If prompted, enter your Apple ID password to reinstall the app. Relaunch the app.