The Android distribution Replicant has recently decided to include the CAcert root certificates in default installations.

Replicant was started as a pragmatic way to achieve software freedom on mobile devices, providing a fully free version of Android. Over the years, support for a dozen of different mainstream devices was added.
However, most of these devices are severely flawed when it comes to software freedom, privacy and security. Thus, it was decided to focus the development effort of Replicant for a few specific devices that perform better regarding those aspects, instead of trying to catch up with the latest mainstream devices. Replicant is sponsored and supported by the Free Software Foundation.

For further details on the inclusion status of CAcert’s root certificates in other OS distributions see wiki.cacert.org/InclusionStatus