Apple Watch has fantastic support for converting speech to text. However, there isn’t any direct API access to the text to speech engine in WatchKit. You can get access to it in your apps though via the Apple provided text input controller.

You can open a text input controller via WKInterfaceController’s PresentTextInputController method. For example, here’s how I show a list of golf course names to start a new golf round in my app GolfWatch:

PresentTextInputController (courseNameList.ToArray (), WKTextInputMode.Plain,
    delegate(NSArray results) {
        // ...
    }
});

In this case a list of course names is displayed along with a button, which when tapped opens a ui to receive speech input. The results are passed to the completion method specified in the third argument to PresentTextInputController. If you only want speech input, simply pass an empty suggestions array in the first argument and the user will be taken directly to the speech input screen on the device (speech input isn’t supported in the simulator).