I wrote this when I was a teenager, primarily to learn PHP and other web technologies. I designed it for my mother, a freelance journalist, based loosely on the paper system she was using at the time, to keep track of income and expenses throughout the year, thus simplifying the process of producing a tax return at the end of the year. She also requested some functionality relating to keeping track of income due to her that had not yet been paid, and the ability to show the contact details of her debtors so that she could chase them up.
For this work, I didn't use a framework of any kind. PHP frameworks were still in their early days, and I didn't know about them. The JavaScript here is almost non-existent: I tried to avoid using JavaScript altogether, and only conceded where it would make a big difference to usability.