Visual for Blocked Calls

I don't know if this can be done but I want to develop an app that sends a cartoon pic to numbers you have blocked on your phone. Or if you can't block the number on your smart phone, this app will automatically send the pic everytime the person calls (until they get the point). Example-you have an ex friend or annoying person whose number you have blocked (from receiving calls) or you don't want to answer. When this person calls, a cartoon image  (of your choice) is sent to their phone ( a limited selection of images to start but I'm thinking-a big red X, a person "mooning", the words "Beat It" or "Go Away") to let them know their call has been blocked/ignored.Their call is not forwarded to voicemail.  I'm thinking you input the undesireable person's number into the app. When the person dials your number, it triggers the app to send the picture (with sound, if you'd like) that their calls are being blocked or ignored.  I'm guessing that would work for people who have smart phones. But most people today are purchasing smart phones because of their functionality.