URL Genius Published a Major Study on Trackers in Mobile Apps
Experts at URL Genius published a major study on mobile apps and found which ones collect the most user data. TikTok turned out to be the “leader” among social networks, with most trackers identified in the “Newspapers” category.

The study was performed using the built-in iOS app activity logging functionality, which allows you to track domains that apps interact with.
Experts confirmed that in most cases, applications communicate not only with their own networks, but also with third-party networks, the origin of which is quite difficult to determine.
The researchers drew attention to 200 popular apps from 20 App Store categories.
The study was conducted on iOS devices and not all installed apps were blocked from collecting user data. Each app was launched once with minimal interaction and then closed.
The researchers did not go through the authorization process and declined all forms of account creation. Reports were recorded in screenshots and all data was recorded in a dataset.
The general results of the study:

Most trackers appeared in Banking category apps, while 93% of domains belonged to third-party resources;
The ranking of “leaders” by total number of online contacts is as follows – iHeartRadio (56 contacts), Wall Street Journal (48), ESPN (42), Popeyes (42), WattPad (36);
Apps with fewer online contacts include Whatsapp (1), Zoom (2), MyChart (2), DuckDuckGo (3) and Bank of America (3);
DuckDuckGo (100% of contacts with special services), Google Play Books (100%), Google Classroom (100%), Microsoft Onenote (100%), Google Drive (88%) Contact at least third-party domains.
Results in category “Social networks”:

In total, we reviewed 10 popular apps in this category, including YouTube, TikTok, Telegram, Whatsapp and Snapchat;
6 Contacts is the average number of online contacts for apps in the category. 60% of them are third-party domains and 40% are proprietary;
YouTube and TikTok are the ones that most interact with external networks, with 14 contacts per app. At the same time, YouTube has 10 of them related to its own resources and 4 to third-party resources, while TikTok has 13 third-party resources and one of its own;
Facebook, Snapchat, Messenger and Whatsapp make a connection.
Results in category “Newspapers and Magazines”:

A total of 10 popular apps in this category were analyzed, including HBR Global, Cosmopolitan, Time Magazine, The New York Times and The Wall Street Journal;
On average, 28 contacts were found in the applications: 93% – with third-party services, 7% – with their own;
The WSJ app had the most contacts, with 48 contacts, 45 (94%) of them from third parties;
Wired Magazine has the fewest connections – 8.
Results for category “News”:

A total of 10 popular apps in this category were tested, including CNN, The Washington Post, NBC News, NPR and Fox’s News;
On average, there were 22 contacts in the applications: 90% – with third-party networks, 10% – with own networks;
CNN scored the highest number of contacts – 34, of which 29 (85%) were related to third-party resources;
SmartNews has the least number of contacts – 8.
Results for category “Food and Beverage”:

In total, we reviewed 10 popular apps in this category, including Popeyes, Publix, McDonald’s, DoorDash, and Uber Eats;
Average number of contacts – 19: 92% with third-party domains, 8% with own domains;
Popeyes links to 42 domains, which puts it at the top of the list. All domains are from third parties;
Uber Eats has the lowest number of contacts – 4.
Results for category “entertainment”:

A total of 10 popular apps in this category were tested, including Hulu, Disney+, Netflix, Ticketmaster and HBO Max;
Average of 20 contacts per app: 69% – third-party services, 31% – own;
Hulu has the most links with 31. Three-quarters of the aliases point to third-party domains;
Netflix has the fewest connections with 9.