Introducing my own Unity asset: Resolution Magic 2D!
Resolution Magic 2D takes the pain and work out of making your game fit on all those differently sized and shaped screens that your millions of potential customers have.
It works like this: you set up your main game area (the part of the screen that ALL players must be able to see), then design your game for that area, and add extra content in a larger area that is optional for players whose screen is a different shape. Resolution Magic 2D also re-arranges your UI objects to keep them at the screen edges regardless of what screen is being used. It’s like magic.