AT&T offers these apps (smartphone only) to help block fraudulent calls and phishing attempts.
PaperKarma is an app and associated service that help stop junk mail. You take a picture of the address label on junk mail and the app magically unsubscribes you from it. The app is free to download, but the actual service costs $2/month. So, save up your junk mail for a year and unsubscribe from it all at once?