One of the first projects I worked on when I launched my independent business was a tracking system for veteran assistance organizations (VSOs). The database was originally built to assist a startup nonprofit keep track of all the veterans they were assisting.
Over time, it grew to accommodate document management, contact recording, education assistance, homelessness assistance, and a whole variety of other functions. Eventually, the clients decided to use SalesForce instead, but it was a good project. (I still offer the product, even if there are no clients.)