Mouse Move Mode is an addon that allows you to use your right mouse button to control the player's movement in Stardew Valley. It works because when you right-click, the player will perform an action on the pointed object when you come near.

This mode was designed to enhance the gameplay by making it easier to move around the map, especially in the cities where there are lots of objects.

The way to install it is to download the ZIP file that is available on the website, and then you can just install it by dragging the file to your game directory.