Aparently a simple calculator, this quite mind-boiling-while-you-build-it application was a greater challenge than initially thought. It was nearly built with jQuery, but looking back now, I'm glad it wasn't, and that AngularJs was the chosen framework.
There were many factors that needed to be taken into consideration in the calculations, such as personal allowance, NI, lower rate tax, higher rate tax, pension, etc.
Luckily, with the help of AngularJs powerful capabilities, and about 60 cups of coffee in total, the application was launched successfully. Fully integrated with Wordpress.
AngularJs, Angular Material, Wordpress, PHP, CSS/SASS, Gulp, Git