Using an iOS device?

New security measures in iOS prevent the user from starting NASA enterprise apps until enabling NASA apps though the settings menu. If you receive the message “Untrusted Enterprise Developer”, then you must perform the following steps to enable NASA apps: 

On your iOS device go to -> Settings -> General -> Device Management -> "NASA" -> Trust "NASA"

(Device Management menu may appear as Profiles or Profiles & Device Management on some device)

Visit Apple support site https://support.apple.com/en-us/HT204460 for more information.

Using an Android device?

After clicking the download link at apps.nasa.gov, you will need to begin installation by selecting the downloaded APK file from the notifications menu or from your downloads app.

You may be prompted to enable “Unknown Sources” to install apps distributed outside the Google Play store.

Unknown sources can be enabled from Settings -> Security -> Unknown Sources