Tip: Double-click window in Apple macOS Sierra to expand and fill

Here’s a cool feature hidden in Apple macOS Sierra. If you double click on the left, right, top, or bottom of a window, the program window will expand to fill the width or height of the screen.

Here’s How

1. Move your cursor to the edge of a window.
2. Wait until your mouse pointer icon is showing up as a left-right or up-down arrow.
3. Then double-click and your program window should fill the height or width of the screen depending on where you clicked.