That's really interesting to know, your app looks awesome. May I ask how long that took you and did you make this in JS? I'll try raising the price of mine for a week and see what the results are thanks.
Same I left MSFT in March to do my own thing! Not just this Windows App tho, it was just a side project while I failed at a startup earlier this year.
I was just thinking that with the state of the how APIs were last year this would have been very tough to do, so I was wondering if you went the JS route since it was in better shape than XAML.
I actually went the JS route because of my skillset. I was was web-dev before I joined MS and never got into XAML much.
The JS platform was pretty stable from the initial public release, I guess that's because it is built on top of IE which has been around much before Win8 came along.
I built this with JS/HTML/CSS but the MathEngine component I built using C# (.winmd) and called into it from the Javascript.
If you have any specific questions about how different parts are implemented, let me know :).