o!pp is a free Chrome add-on developed by TheEZIC. It falls under the category of Browsers and specifically the subcategory of Add-ons & Tools. This program allows users to calculate performance points (PP) for every osu! gamemode, with options to change mods, accuracy, combo, misses, and more. Additionally, it displays beatmap stats.

To use o!pp, users need an osu!api V1 key, which can be obtained from the official osu! website. The add-on also provides an open-source code on GitHub, where users can report issues or make feature requests.

With its ability to calculate PP and provide beatmap stats for every game mode, o!pp is a valuable tool for osu! players looking to improve their performance and track their progress.