Mozilla wants to engage with users more. MMA is the project for this purpose. When a user performs a certain UI action (or set of UI actions), she will see a prompt and have a chance to interact with it. For example, if a user uses Firefox 10 times a week, but Firefox is not her default browser, we'll prompt the user the next time when she launches our app, and guide her to set us as default browser.
Mozilla is using a third party framework called "Leanplum" in order to achieve this. Leanplum is a San Francisco company, founded in 2012. We put their SDK in our codebase via Carthage.
The SDK is documented at https://www.leanplum.com/docs/android
defined by ``com.leanplum.internal.Constants.API_HOST_NAME`` at https://github.com/Leanplum/Leanplum-Android-SDK/blob/master/AndroidSDKCore/src/main/java/com/leanplum/internal/Constants.java#L32
The user is identified by Leanplum using a random UUID generated by us when Leanplum is initialized for the first time. See: https://github.com/mozilla-mobile/fenix/blob/master/app/src/main/java/org/mozilla/fenix/components/metrics/LeanplumMetricsService.kt
Here is the list of current Events sent, which can be found here in the code base: https://github.com/mozilla-mobile/fenix/blob/master/app/src/main/java/org/mozilla/fenix/components/metrics/LeanplumMetricsService.kt
Messages are in-app prompts to the user from Leanplum. The user interaction of that prompt will be sent to the Leanplum backend (such as "Accept" or "Show") to track overall engagement with the Message. The Message is downloaded from Leanplum when the Leanplum SDK is initialized at App start, assuming the fulfillment criteria for the Message is met. As mentioned before, the fulfillment criteria is a set of required Events and User Attributes. The fulfillment criteria are set in the Leanplum backend.