Is it safe to assume that most mobile phones and tablets today have moved to 1280x720 resolution and above and make the games in that resolution, scale down for smaller screens or is a smaller resolution like the often used 800x480 still the recommended way to do it and scale it up for larger devices?
You can make a script at the start of your game to get the
Screen.Height, and then set your camera's scale to the same scale the user is having. You can never assume anything, maybe most mobile phones have moved to 1280x720, or 1280x800, but what about tablets? They're android devices as well, and they should be able to run your games without having some blue borders on the side because the camera can't scale.