As a developer, you often depend on the use of third-party tools, such as Google Analytics or AdMob. This is completely fine, and nothing to be ashamed of. However, you probably have thought much about user privacy. So, this chapter shall tell you about some best practices.
If you use third-party tools, it is best practice to give users an option over this data sharing. Indeed, under EU law, this will often be a legal requirement.
When you implement consent in apps, it is important that you ask for consent before you initialise most of your third-party tools. This is because EU law (the ePrivacy Directive in Article 5(3)) requires you to seek consent before you access or store information in on user’s device, unless such is strictly necessary. Analytics or ads are not usually strictly necessary and thus need consent.
When asking for consent, make sure you make it for end-users as easy to decline as it is to accept. This means that you should use the same colour for both options and also use neutral (and not leading) language for these options.
A good overview of how to implement consent is provided by the French data protection authority at https://design.cnil.fr/en/concepts/consent/.
In implementing consent, you might be playing with the idea of using a consent management platform (CMP). While some CMPs have good features, they can also introduce additional compliance risks. This is because CMPs often involve a significant amount of additional data collection before consent is given. This is why it is better, if you can, to implement the consent flow yourself. This is not complicated. Sample consent implementation for consent on Android can be found on GitHub. For example:
At best, you should use as few third-party services as possible. If you do, you have some options to improve user privacy.
Adjust. Once the Adjust SDK is enabled in your app, data sharing takes place, notably of device events. User consent should be established before enabling this SDK. It stands out that Adjust integrates the GDPR right to deletion into their SDK. This could be implemented in your app, to show your efforts to comply with GDPR.
More info: https://github.com/adjust/sdks
AppLovin. For EU users, AppLovin requires consent to be passed on programmatically. If consent is given, the Advertising ID and IP address will be sent to advertising partners, otherwise only a country code. Once loaded at runtime, AppLovin automatically receives the information that the app was installed.
More info: https://www.applovin.com/gdprfaqs/
AppsFlyer. The service collects the Advertising ID and a unique AppsFlyer user ID from the first app start. User consent should be established before activating this service. If the Advertising ID cannot be accessed, permanent identifiers, notably the device’s IMEI, are shared with AppsFlyer, unless programmatically disabled. Such permanent identifiers are highly critical from a data protection standpoint. This practice should be communicated transparently to the user, if not disabled.
Facebook SDK. From the first app start, the Facebook SDK collects device information and events (app installation, app start, in-app purchases), unless programmatically disabled. User consent should be established before activating this SDK. Facebook serves no advertising, if the user limits interest-based ads from the device settings.
Flurry. For ads, this service provides a complicated mechanism to establish a user consent. Since legally required for many advertising services, you may want to consider easier, alternative approaches to establish valid user consent. Unless programmatically disabled, the user location is collected for analytics purposes, if the app has the permission to retrieve such. This is highly invasive and may violate GDPR. At very least, this practice should be disclosed to the user transparently, if not disabled. Generally, user consent should be established before activating this service.
More info (Analytics): https://developer.yahoo.com/flurry/docs/analytics/gdpr/summary
More info (Ads): https://developer.yahoo.com/flurry/docs/publisher/gdpr/
Google AdMob. This service serves personalised advertising by default, violating Google’s policies if used in the EU. This must be changed by the developer, such that user consent is established prior to serving personalised ads. AdMob shares device statistics and events with Google from the first app start, unless programmatically changed. User consent should be established before activating this service.
Google Analytics. User opt-out and IP anonymisation are supported programmatically and their implementation should be considered. User consent should be established before using this service.
Google Chrashlytics. This service shares crash reports with Google from the first app start, unless changed by the developer. User consent should be established before activating this service.
Google DoubleClick. This service serves personalised advertising by default, violating Google’s policies if used in the EU. User consent should be established before activating this service.
Google Firebase Analytics. This service collects device statistics from the first app start, unless changed by the developer. The collected data includes the Google Advertising ID, unless programmatically disabled, and may be used for advertising purposes under certain circumstances. User consent should be established before activating this service.
Inmobi. The Inmobi SDK only collects personal data, if you explicitly indicate to the SDK that user consent was established. If no consent is given, unpersonalised ads are shown to the user. Inmobi encourages you to provide data about location and demographics for higher revenue, if you programmatically pass on this information. Such sensitive data collection should be transparently disclosed to the user, if not refrained from.
MoPub. For increased advertising revenue, MoPub shares data with two other services, IAS and Moat, unless programmatically disabled. These services must be transparently communicated to the user, if not disabled. User consent should be established before activating this service.
Unity Ads. Unity automatically asks for user consent, unless a special arrangement is reached with Unity. Personal data is only collected if the user consents. When ads are served, Unity provides the user with a “privacy icon”, to change his opt-out setting. If the user opts-out, all collected data is deleted.
More info: https://unity3d.com/de/legal/gdpr