Citigroup announced Monday a feature in pilot that lets customers check deposits, credit card balances and recent transactions on a mobile device without having to log in to the bank's app.

The new opt-in tool, called Citi Mobile Snapshot, is expected to be introduced to all of the bank's U.S. customers by yearend. Users can view their balances and 15 most recent transactions without having to enter their user name and password.

The news comes at a time when banks nationwide have been designing newer ways to authenticate individuals on a device with limited real estate. Bank of the West, for example, also lets people view account balances with a single gesture, while Capital One lets mobile in with pattern passwords.

Other banks are exploring biometrics like voice recognition and device fingerprinting to authenticate customers.