PandaHunt is a problem classifier utility, designed to aid in practicing of competitive programming problems. URL : http://onlinejudge.net84.net/PandaHunt/index.php

As of 15 January 2014,
Problems : 18407
Users : 16

Features :
1. Adding/Deleting of tags
2. Searching of problems by name, code, title, author, resource and tags
3. To-Do List of problems (Only after login) 4. Filter by Online Judges

Screenshots :

Online Judges Supported:
1. UVa Online Judge (Website)(Checking for accepted problems not supported yet)
2. Sphere Online Judge (Website)
3. CodeForces (Checking for accepted problems not supported yet)
4. Tianjin University Online Judge (Website)
5. Saratov State University Online Contester (Website)
6. Peking University Online Judge (Website)
7. Timus Online Judge (Website)
8. Zhejiang University Online Judge (Website)

More features will be implemented, and more problems will be added.
Please comment below if you have any requests, comments or remarks to make. Thanks a lot :D