How secure is my information with the American Express App?

Your information is sent to American Express Company using end-to-end encryption. However, please note that American Express does not operate or control the wireless networks used to access the American Express® App. Network security and protocols may vary. Check with your wireless service provider for information about their privacy and security practices. Your account data can only be accessed via the American Express® App using your User ID and Password. However, to further improve security you may also choose to set a passcode for your Android phone or iPhone as a further precaution.