ember-gesture-modifiers is an Ember.js addon that adds gesture handling as template modifiers, currently offering a `{{did-pan}}` modifier for pan gestures. It lets developers attach callbacks for pan start, move, and end events with configurable options (axis, threshold, pointer types, etc.), and includes a test helper for simulating pans. It targets Ember apps (v3.28+) that need easy, declarative touch/mouse gesture support.