Evernote organized an AppleWatch hackathon in Zürich. There I met with Arik, whom I know from previous WWDCs.
We developed an Apple Watch app which helps to learn vocabulary on the go. We use different sensors to determine when the user is idling, for example waiting at a red traffic light. We then push a little exercise notification which includes one vocabulary. This can help to learn a new language on the go without a big effort.