unsolved.wa is a free Chrome browser add-on developed by unsolved.wa. It falls under the category of browsers and specifically belongs to the subcategory of add-ons and tools. The add-on, named unsolved.wa, provides a service for recommending problems for BOJ (Baekjoon Online Judge) ranking and offers a platform for users to contribute to the ranking system.

With the BOJ Extension, users can receive daily recommended problems and contribute to the school/company ranking. The add-on also includes a contribution system that assigns a contribution score to users who solve problems that contribute to the ranking. Users can view their profiles, including Solved Exp, Coin, Organization info, and the contribution ranking for Unsolved problems.

One of the notable features of unsolved.wa is its automatic synchronization with BOJ - Unsolved. When a user solves a problem, the result is automatically sent to the platform.

Please note that unsolved.wa requires access to certain personal information. It utilizes the cookie information used for Solved.ac login, without storing any data in external databases. Additionally, it uses the BOJ user nickname information to measure the contribution level and sends it to an external database.

Overall, unsolved.wa offers a convenient and efficient solution for BOJ ranking and problem recommendations, allowing users to enhance their skills and contribute to the community.