Yes — on Google Play
Amex has a Google Play listing.
App Store
On Google Play
Is Amex on Android?
About Amex
The official American Express App for iPhone allows you to access your Account from anywhere. Track spending & rewards, find offers, review your balance, pay your bill and enjoy features only available in the Amex App. Touch ID and Face ID login (on supported devices), gives you quick, safe and secure access. Make the…
Amex is listed on both the App Store and Google Play from American Express, so you can install it on Android phones and tablets. The Play Store listing shows 100,000+ installs.