Algo Plus provides a platform on Baekjoon Online Judge where users can practice coding tests and utilize a handy feature called the error note. This tool is designed to help users prepare for real coding tests by offering an environment to practice on Baekjoon Online Judge and reduce common mistakes using the error note feature.

With support for 11 languages, Algo Plus offers an editor and compiler environment where users can run test cases. Users can compare two codes, select specific areas to add comments, and create error notes. The completed error notes can be uploaded to a GitHub repository.

Algo Plus not only provides a coding test environment but also allows users to save error notes on a GitHub repository, compare two codes, add comments to specific code areas, and save error notes in Markdown format.