Shariff Wrapper was updated to include StumbleUpon successor Mix.
Operator and developer Jan-Peter Lambeck has updated the Shariff Wrapper to include Mix.

Update your wordpress site to include Shariff Wrapper’s Mix:

Join Wix by pointing your browser to StumbleUpon with your usual credentials, update or reselect your preferences and your set:

Don’t forget to add Mix to your Shariff Wrapper setting though.