Twitter is joining the “graph” bandwagon, announcing that it will soon start looking at which other apps you’ve installed on your phone to build a more personalized experience.

Twitter says this will serve you a more “tailored experience,” including “who to follow” suggestions, relevant tweets, and other content it adds to your timeline, as well as its promoted content. Twitter also says that it’s not collecting any data within the apps themselves, only the apps that are present on your phone.

In fact, Twitter will show users a prompt informing them that “to help tailor your experience, Twitter uses the apps on your device” once the feature is turned on for them — until then, it’s not collecting this data. If you’ve previously turned on “Limit Ad Tracking” on your iOS phone or set your Android phone to “Opt out of interest-based ads,” this feature will be automatically turned off.

While Twitter has declined to comment about whether this might frustrate its mobile users and cause some of them to uninstall the app, it’s hard to believe it won’t make others concerned. And of course, if you prefer to keep the app but disable the data collection, Twitter offers easy instructions on how to turn it off. (There is an opt-out feature for iOS and Android users.)

The added “personalization” (read: targeting) approach will likely help Twitter better service its advertisers. The company has been working hard to focus on mobile and its mobile revenue, as we’ve previously reported; helping its advertisers target their ads even better is an obvious way to keep at this.

The App Graph could also come in handy as Twitter forges ahead with its plans to start “filtering” your timeline, Facebook-style. Earlier this month, the microblogging service said that it’s experimenting with showing users a “snapshot” of the most important news and content in their timeline to save them from having to scroll multiple tweets when they open the app. Twitter said it could use “who you follow and what you engage with” to do this, so the apps on your phone could also be helpful.