Twitter will begin collecting data on which apps its users are downloading in order to build a "more personal" experience, Recode reported.
In the Security and Privacy section of its support site, the company says that it will be "collecting and occasionally updating the list of apps installed on your mobile device so we can deliver tailored content that you might be interested in".
The move will help Twitter better target its 'promoted posts', but the company says it will also improve its suggestions for accounts to follow and adding "Tweets, accounts, or other content to your timeline that we think you'll find especially interesting".
Twitter has assured users that it will only track which applications you have installed, not any data from within the applications.
The benefit for advertisers to better target users is obvious: Twitter users with Jawbone UP24 installed could find more fitness-related ads, while music subscriptions services could target users of their rivals with special offers or incentives to switch.
Twitter isn't the only service to be tracking it users' apps. Facebook checks which apps users have installed that use the Facebook SDK -- again to better target advertising of Facebook games and applications. WhatsApp will also retrieve a list of applications you have running.
If this all sounds a little too much, Twitter does point out that this is entirely optional -- you can turn off this feature, and the company details exactly how to do so for both Android and iOS on its website.