Twitter is collecting information about the apps installed on your smartphone or tablet to serve you better ads.
Called App Graph, the update will keep track on the applications on your device, but won’t collect any data from the apps themselves.
App Graph is opt-out, and Twitter will prompt you when it’s tracking your data, so you will be able to opt out at that time. If you haven’t seen the prompt then Twitter says it isn’t yet tracking your device.
Here’s more on how it works, courtesy of Twitter Support.
To help build a more personal Twitter experience for you, we are 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. If you’re not interested in a tailored experience you can adjust your preferences at any time. Additionally, if you have previously opted out of interest-based ads by turning on “Limit Ad Tracking” on your iOS device or by adjusting your Android device settings to “Opt out of interest-based ads,” we will not collect your apps unless you adjust your device settings.
The update rolled out to iOS users yesterday, and will appear on Android devices in the next week.