With the tellows app, you can now identify unknown callers!
The app will tell you real-time if the call is trustworthy or not. On the first ring of your phone, the tellows score will appear in order to help you decide whether to answer the phone or cancel it – 7 to 9 being the most untrustworthy numbers. The app also allows you to read the comments of users about this number. Post your own complaints through this app so you can also warn others. The service is free of charge.
The only requirement is of course, aside from internet access, is an Android Smartphone or an iPhone.