See GitHub: Stack Exchange, replace badge icons with duckies... and post bug reports and pull requests there.
Install: Install from GitHub
Made some tweaks as follows:
June 01, 2019:
Turned on styling for network-user pages.
Fixed a race condition / GM_addStyle bug whereby the styles were not sticking for certain page loads.
November 16, 2018:
I don't know for sure what the original problem was, but the most recent issue was a result of implementing a new badge without rebuilding the API. Once the API was pushed to production, the bug was resolved. If it happens again (especially if there's a new badge) please let me (or really any employee) know. We can contact a developer directly.
From a ...
Could you add progress towards the Enlightened and Guru badges for answers too?
These would list accepted answers that have scores close to 10 and 40 respectively (with the Enlightened candidates limited to first answers only), as well as list not-yet-accepted answers where the score (and "first answer") criteria have been met and would qualify for just ...
The Informed badge is removed from the "Next badge" tracking. Previously it was listed in the Available badges section. Now it is not available under the Available or Bronze section. So the bug has been fixed recently.
Screenshot for reference:
Copied from the MSE answer
This seems to have been silently/magically fixed in the last 7 months (Date of Nicos Karalis' comment).
Descriptions seem correct now. I had verified that they weren't correct when I upvoted this question on Apr 29 '14.
Side note: It's not documented, but apparently tag-based badges are not listed unless they have been awarded at least once.
Take a look ...
Badges and new privileges are part of the /notifications method, which is a single call for all accounts across the network. The results show whether the notification is unread or not. There's also a separate method just for unread notifications: /notifications/unread.
For reputation changes, all I know are some site-specific methods (/me/reputation, /me/...
Could the Sportsmanship badge be tracked with this application? I know data.SE can't, but an authorized app like this might be able to access more data? (As you can see, I don't really know anything about stack app development. I very much like your app, though, thanks for that!)
The page does not seem to work in Opera 12.10. I get the following error in the error console:
Event thread: message
Uncaught exception: TypeError: Cannot convert 'bodyinject' to object
Error thrown at line 1757, column 2 in injectcode():