The update brings the app up to version 2.0, and outputs at 3840 x 2160, with the BBC UHD logo in the top-right corner of the display. At present it's only a live service, so there's no option to watch a show from the beginning if you've missed the start.
The launch comes just a few days into the 2018 World Cup finals, with England's opening game against Tunisia among the first programmes to be available on the new and improved app.
However, it hasn't been all plain sailing for the BBC's 4K content rollout. Many viewers complained of an intermittent or poor service during the first few available 4K World Cup games.
While the BBC is showing all of its 29 games in 4K, there's a limit on the number of people who can tune in at the same time as the BBC stress-tests its new service.
As well as buffering and audio issues, some viewers complained of a lack of contrast and brightness in the image produced. At least one member of the TechRadar team missed Harry Kane's first goal in the England vs Tunisia match as a result of a dropped stream, and even when the service is working properly there's a delay of a few seconds, so those looking to get the most up to date playback may want to look elsewhere.
- How to watch the World Cup finals: livestream every game from anywhere