What The Hell, Twitter?
Jack Marshall, writing for WSJ.com:
Twitter is now collecting information about the apps installed on users’ devices in order to better target and tailor advertising and other content to them.
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 (read below). 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.
I have always enabled the “Limit Ad Tracking” option on all of my iOS devices.