Check this :
It is not like the last time you used the app itself like WhatsApp, but your actual device. Also, it does this without your consent.
Not cool, huh? You can stop it just like this :
If you don’t like other people having access to this information, you can either uninstall the app or you can stop the application from running in the background.
Read More : http://vikitrendz.blogspot.com.ng/2017/03/major-specification-differences.html
For iPhone, go to Settings and then General, select “Background App Refresh” and look for TrueCaller. Then, simply turn off the green-colored switch.
For Android, go to the Apps menu in Settings, select True Caller and tap “Data usage.” Then, tap the three-dot menu button, select “Restrict Background Data,” and confirm.