Truedialer looks up unknown contacts as you punch in their phone number

The folks behind Truecaller, a popular app for identifying and blocking marketers and other spammy phone calls, have launched a new dialer app for Android that makes good use of their existing contacts database. With it, you can look up contact information of the person you're actively calling, even if they aren't in your address book. Spooky? Maybe. Useful? For sure. Once the data has been fetched, you can import that contact to your device painlessly.

source: androidcentral