# Telemetry Fenix uses Mozilla's telemetry service (Glean) and LeanPlum to measure feature performance and engagement. ## Glean pings and metrics By using the Glean SDK, Fenix can send the pings the SDK owns and defines, as documented [in the Glean SDK docs](https://mozilla.github.io/glean/book/user/pings/index.html). Additional metrics or pings defined by Fenix are documented in the [Glean SDK autogenerated docs](metrics.md). ## Leanplum See [here](https://github.com/mozilla-mobile/fenix/blob/master/docs/mma.md) for details on Leanplum usage in Firefox for Android. ## Crash reporting See [here](https://github.com/mozilla-mobile/fenix/blob/master/docs/crash-reporting.md) for details on crash reporting in Firefox for Android.