Even though this is its main purpose, CallApp - Caller ID and Block offers many other features as well. The most interesting lets you use this app as your contacts book, with all the info you could need about your contacts. Through its interface you can quickly access the profile for any of your contacts from any social network.
Using CallApp - Caller ID and Block, you can link your contacts with their corresponding social network profiles. Thus you just have to access your friends' profiles to also be able to call them through Skype, send a text, chat through Facebook, or send them a tweet. You can, in short, transform this app into your main social app.
CallApp - Caller ID and Block is a contacts book full of interesting features, thanks to which you can easily stay in touch with anyone.
Requires Android 4.0 or higher