This app is aimed towards the massive and quickly growing population of American workers that depend on an unstable paycheck, most living paycheck to paycheck. The amount of hours they work can change drastically from week to week. Being able to accurately calculate what their paycheck will be next week is a game changer for these workers. Knowing that information early on is essential to planning spending and staying within budget.
Of course the app also works just as well for those with stable jobs. Planning on a promotion or switching jobs? Having a realistic idea of what you will be making is a powerful tool.
While apps similar to this already exist, they are either of poor craftsmanship or geared towards the business owner calculating paychecks for employees (not the individual).
The biggest road block was the lack of easily workable tax information (tables). I had manually extract the information from multiple sources (PDF documents from the IRS and State). This was no easy task, it took many hours to ensure I didn't make any mistakes during the process, as one mistake could screw up calculations massively. Along with this road block, I also had to learn new technologies (Meteor, SlimFramework) and figure out how to properly calculate income taxes.
I'm happy to say that no one else should run into this issue. All of the extracted information for New York and the Federal Government is available for free, open source. Also, my server (hosted by Microsoft Azure) is running an HTTP API, which computes and returns detailed information about each tax amount and the estimated net pay.