As I mentioned previously on how to update Chrome Web Apps, there are very limited help documents from Google on this kind of miscellaneous things. So since my customer might need this information sometimes in the future, I’d like to make it available to everyone.
Here’s how you do it:
Open a new tab which lists all your app, click the little setting icon on the top right of the application icon you want to reinstall, and click Uninstall on the popup menu.
Then when you go to the app’s listing page on Chrome Web Store, you will be able to install the app again. If the app (like OhBoard) is paid, you don’t have to go through the checkout process again.
Let me know if you have any troubles doing that.