You can change 3 items related to your contact on another persons phone.
"I just called to say" is an app that is designed to give people who care about each other a new way to express their emotions through a mobile app. The app through a secure handshake, allows user A to change 3 of user A's contact related entries on User B's phone without their knowledge. You may "surprise" them with a ringtone/profile name/profile photo without their knowledge. You may also send Greeting Cards via this app to all people on your contact list. You may "distrust" any contact at any time if you choose to you. I plan to add new greetings regularly keeping the gallery fresh & fun. This is an ideal way to surprise your loved one or friend. You can also record your voice and send this voice note as a ringtone. To add some humour you may convert this voice to a Chipmunks voice and send this. Imagine waking someone up with a chipmunk voice telling them its time to get up :)