YouMail is a visual voicemail service that works on your iPhone, Android, and on the web. You can also get to your voicemails right from your email inbox. Then you can easily reply to them, forward a message to someone else, save it, or archive it.
YouMail takes call blocking to the next level. Instead of just preventing unwanted callers from getting through, you can choose from a variety of pre-recorded messages that they'll hear. For instance, if you're having issues with telemarketers, you could have it play a message saying your phone has been disconnected.