WatchKit Double Tap

Sadly there's no double tap gesture in the current WatchKit version. It is possible though to manually detect double taps.
This isn't possible with a button because the system doesn't send all tap events if one is too fast. But with a table we get all the taps unfiltered and can now messure the time between taps and detect double taps.

Just create a table with one row and put whatever you want tappable inside that row.

@implementation InterfaceController {
    NSDate* _lastTouch;

- (void)table:(WKInterfaceTable *)table didSelectRowAtIndex:(NSInteger)rowIndex {
    OverlayRowController *rowController = [table rowControllerAtIndex:rowIndex];
    if (_lastTouch && [[NSDate date] timeIntervalSinceDate:_lastTouch] < 0.4) {
        // double tap
    _lastTouch = [NSDate date];

Simple as that. We store the time for each tap and if the last tap was < 0.4s ago we consider it a double tap.