EDIT: the issues I mentioned below have still not been addressed. For this reason, my rating has been adjusted to one star to reflect the lack of consideration of customer reviews.
This app works...
However, it doesnt work together with the other StumbleUpon services.
1) There is no way to paste a copied link within the app to a Stumble the user may have been viewing in browser.
2) The emailed Recommended Stumbles are automatically opened in browser when clicked. This normally wouldnt be an issue if the website had an "Open in App" button.
3) The whole reason (1) and (2) are issues is the fact that the StumbleUpon website does not work well on mobile (or at least iPhone). Some pages automatically refresh or whiteout every 60 seconds or so causing the user to have to refresh, making it difficult to finish viewing a Stumble.
I believe fixing these issues can make for a better experience.
BR,
AJ
Select_Me about StumbleUpon, v5.3.0