The website if offline but the app is still on Play Store (guess probably forgotten) The idea can be good (tell your contact "I'm going to call you to...) so you're not losing the call or get notified to call later etc but I really can't see the need of an app for that.
I was expecting something more "virtual" like a customized caller ID with a message (not sure if it's actually possible like with sms...) but definitely not an app to keep
