Great snow effect. The developer was quick to respond when I couldn't get the effect to stop after I deleted the app. I had to re-install it and switch the button to off. Then I deleted it again. Here are the instructions the developer sent me:
Thanks for your email on removing Holiday Snow from your website.
You can turn off Holiday Snow by:
1) Visiting - http://holidaysnow.herokuapp.com
2) Click the single control on the page so that it's in the "Snow Off" position.
Please note that uninstalling the app will not remove the "Snow Effect".
You must first turn off the snow per above. "