If you want to know more about the kind of data Apple’s in-house apps track on you, the company has released a publicly available database for that very purpose. This database is searchable through Apple’s privacy website under the Labels section, and offers clear details about data tracking when it comes to iOS, iPadOS, macOS, watchOS, and tvOS apps.
This is what it looks like.
What's different this time? — Apple's privacy labels program isn't exactly brand new. In the past, users were able to see the kind of information in-house apps gathered by visiting their separate support pages. Under those individual support sections, you could get information about what kind of data an app gathered on you, from contact information to your search history.
For example, if you were to look at the individual label section for an app like Apple's Clock, you'd be able to see identifiers linked to you. Under this new iteration, however, Apple is consolidating the entire endeavor into one searchable database, which makes it much easier for people to go through. You can search Apple's alphabetically ordered database from A to X and see the kind of data an in-house program gathers on you.
A quick search of Apple Books in the A section will show you that Apple gathers information on the purchases you make for book titles, your search history, how much time you spend on Apple Books, contact information, and financial data. Apple does note that the nature of data collection depends on individual cases. “The data collected from you may also vary from what is displayed in this section,” the company states. “For example, collected data may depend on the features you use, whether you only use a paid version of an app, or whether you’re a child.”
Apple content with making enemies — Apple's push for data transparency has most likely had a favorable effect on users but it has caused undeniable friction with competitors. Facebook, which has a tracking tool that should worry any user concerned about privacy, has essentially slammed Apple's transparency efforts as anathema to web tracking, which gives developers and advertisers access to everyday users’ data.
With this database accessible to anyone interested, Apple might eventually consider creating an open library of labels for third-party apps, giving users an even clearer look at the information gathered on them.