A free app for Android, by inibahagia.
This app is a guide for couples and has nothing to do with WhatsApp. The guide is based on a principle that we've been using for years and that is, if you know who is calling or texting you, you can find out who it is with the same app.
The principle is very simple and works with any type of phone, no matter if it is an Android or an iPhone. The only thing you need to do is install the app and give it your contact list.
After you give it a name you can start to look at the profile of the person that is calling or texting you.