Ad SDKs and Trackers: What a Free Kids' App May Collect
Many free apps are built from your developer's own code plus several pieces of third-party code, called SDKs, that handle ads, crash reports or usage analytics. Those pieces can collect data about the device and how the app is used. In an app made for children, special rules apply, but it is still worth knowing what sits inside, and how to check before you install.
- An SDK is a ready-made code package an app includes; ad and analytics SDKs often come from companies other than the app developer.
- What an SDK can collect depends on the app's permissions and on what the developer enables.
- Apps aimed at children have extra requirements on Google Play and under children's privacy law such as COPPA in the US.
- The Data safety section, the ad label and the permission list are the quickest checks a parent can make.
What an SDK is
An SDK (software development kit) is a bundle of code that a developer adds to an app to get a feature without building it. Common ones handle:
- Advertising: choosing and showing ads
- Analytics: counting sessions, screens and taps
- Crash reporting: sending error details to the developer
- Sign-in and payments: connecting to other services
This is normal and often harmless. The point is that the app's behaviour is partly decided by code the developer did not write, so the app page alone does not tell the whole story.
What they may collect
It varies by SDK and by configuration. Commonly discussed examples include a device or advertising identifier, approximate location, the type of device and operating system, and which parts of the app are used. What an SDK can reach is limited by the permissions the app holds, so an app with fewer permissions has fewer things to share. Our permissions guide explains how that works.
We cannot say what any particular app does from its listing alone. The safest approach is to read what the developer declares and compare it with what the app asks for.
Extra rules for children's apps
Google Play has a program and policy for apps designed for children and families, which sets requirements on how those apps handle ads and data.[1] In the United States, the Children's Online Privacy Protection Act (COPPA) limits how online services collect personal information from children under 13, and the FTC publishes guidance for businesses.[2] These rules apply to apps that are directed at children; a general-audience app may follow different ones. Rules also differ by country.
How to check an app before installing
- Read the Data safety section on the Google Play page. Developers declare what data they collect and whether they share it.[3] It is self-reported, so treat it as a claim.
- Look at the ad label ("Contains ads") and the age rating.
- Review the permissions. Anything that does not match the app's purpose, such as location in a colouring game, is a reason to pause. Check them in App Checker.
- Prefer apps from known developers and with a clear privacy policy.
- Revisit after updates. An app can change what it collects.
Practical steps for parents
- Choose fewer, better apps. Each extra app is another set of SDKs.
- Limit app permissions on your child's phone; see how to review permissions.
- Reset or limit the advertising ID in your Android settings if your version offers it.
- Browse the App Directory to compare ad labels and permissions for popular apps.
Frequently asked questions
What is an SDK in a mobile app?
A software development kit is a package of ready-made code a developer adds to an app to provide features such as ads, analytics or sign-in.
Do free kids' apps always track children?
Not necessarily. Apps for children have extra requirements, and many collect little. The Data safety section and permissions show what the developer declares and what the app asks for.
What is COPPA?
The Children's Online Privacy Protection Act is a US law that limits how online services collect personal information from children under 13. Other countries have their own rules.
How can I tell if an app contains ads?
The Google Play listing shows a "Contains ads" label for apps that include advertising.
Can I stop an app from collecting data?
You can limit what it can reach by tightening permissions, avoid giving it extra information, and uninstall it. You cannot always see exactly what is collected, so choosing carefully matters.
- Designed for Families — Play Console Help — requirements for children's apps on Google Play.
- Complying with COPPA: Frequently Asked Questions — Federal Trade Commission — FTC staff guidance on the COPPA Rule.
- Provide information for Google Play's Data safety section — Play Console Help — what developers declare about data collection.