Why are there black bars on the sides of the screen when I use GeForce NOW on my Android device?

GeForce NOW streams at many resolutions, including 1280x720 and 1920x1080 which have a 16:9 aspect ratio. Most newer phones have a wider resolution, such as 3040x1400, which has an aspect ratio of 18.5:9. On these phones, people will see black bars on the sides of the screen. We are looking into supporting additional aspect ratios to eliminate these bars in future software updates.