Truecaller, a really popular phone book/caller ID application, is hugely popular in India. Taking advantage of the user base here, the company has announced a partnership with Twitter for an unique integration into its app. Users can now tweet or follow their contacts, or any number associated with a Twitter account, right from inside the Truecaller app. This unique integration is even more special, as it starts its roll out for Android users, first in India. In a bid to increase engagement, Twitter seems to have handed over its private APIs for accessing stored mobile numbers to Truecaller, as a part of this partnership, so that they can use it for this integration, again, starting with India. This is a genius move for courting the vast number of Truecaller users to Twitter, which is already gaining huge popularity in the country with sports, politics and Bollywood topics being the rage. The update also brings a clean new design and is immediately available for Android, with the iOS version slated for a 2014 release, with no solid dates for other platforms.