Companies was my second paid plugin. It was made on request and also one of my first commissioned plugins. The initial goal was to provide an alternative way of trading. Instead of offering what players have, they could simply put up an order and a single player or a group of players called company could then fulfill those requests.
The goal of the whole system was to be easy to use and avoid any exploitation from user side. A user can add multiple items into an order and each item has its own price assigned. Players then get paid based on the items they contributed and its value. This makes it a fair payment and players will get exactly the value they contributed.
Orders are also completely anonymous, and either the company fulfilling them or the user ordering the items know who fulfilled or ordered those items. This makes it impossible to boycott certain players or in general to call out or pressure other people.
Additionally, this is my first plugin, which allows to be run on multiple servers, but sharing a database.
Of course this whole plugin is also configurable and usable by text UIs. A user only needs to know two and an admin three commands.