Duplicate Artboard Below.sketchplugin

// Duplicate Artboard Below (alt ↓)

current_selection = selection[0];

if (current_selection.className() == "MSArtboardGroup") {
  var parent = current_selection;
} else {
  var parent = [current_selection parentGroup];
}

var artboard_copy = [parent duplicate];

[[artboard_copy frame] addY:[[parent frame] height] + 100]

[artboard_copy select:true byExpandingSelection:false]

Duplicate Artboard Right.sketchplugin

// Duplicate Artboard Right (alt →)

current_selection = selection[0];

if (current_selection.className() == "MSArtboardGroup") {
  var parent = current_selection;
} else {
  var parent = [current_selection parentGroup];
}

var artboard_copy = [parent duplicate];

[[artboard_copy frame] addX:[[parent frame] width] + 100]

[artboard_copy select:true byExpandingSelection:false]