I like past tense because it what en event is. A notification that something happened. I just made a search for  this.emit(' in the project and I found stupid inconsistencies. For example our model emit this.emit('change', keys) and our storage library this.emit('changed', value);  Our timer library emits this.app.emit('timer:started'); this.app.emit('timer:ended'); but your pinch module emits pinchstart / pinchend. These inconsistencies make the code annoying to work with.