Install
Install the latest version of SMAPI.
Unzip the mod folder into <font style="font-family:Courier New;">Stardew Valley/Mods</font>.
Run the game using SMAPI.
Use
Press <font style="font-family:Courier New;">Space</font> (configurable) to jump; do it while walking towards something (like a fence) to jump over it.
Compatibility
Compatible with Stardew Valley 1.5.5+ on Linux/macOS/Windows, both single-player and multiplayer.
See also