As you may know, Canonical has been working a lot at its Ubuntu Touch lately, the OTA-6 Update is now being tested.
The first promotion candidate has been released, but Canonical will perform some more tests and won’t make this the final version of the update.
Also worth mentioning, Canonical’s new super fast and scalable thumbnailer will be implemented in OTA-6.
As a reminder, Ubuntu Touch is a stable operating system, but it is not mature enough, compared to Android and iOS. For now, there are three Ubuntu Phones: Bq Aquaris E5 HD, Bq Aquaris E4.5, Meizu MX4, but the system is also officially supported on the LG Nexus 4 device.