Startup Idea: Customizable Debt Management Software

Startup idea to develop a robust and customizable debt management software, which will allow the user to include various variables such as zero-interest periods. This allows for more flexibility than the traditional 'all or nothing' approach. The software should also include multiple calculators for testing different debt payment scenarios.

I am currently working towards becoming debt free. With a multitude of debt, I have tried both free and paid software. The problem I have encountered is that with either kinds, it is all or nothing.

What I mean by all or nothing, is that no variables can be entered. It is either use the snowball method (smallest debt to largest) or the avalanche method (where the highest rate interest is paid first).

What I mean by variables, are such things as factoring things like zero-interest for 12 months, etc.

I would like software that would permit me to enter these variables and thus, use more than an all or nothing approach.

Various calculators would also be helpful to determine what is the best approach. I currently use good old fashioned pen and paper. A calculator is used for playing around with different scenarios. Having a rock solid plan would be super beneficial.