Writing a really good app that is both enjoyable for students and a rigorous test of ability that employers are looking for is not chump work.
If you can show employers that your app truly tests useful abilities they would be lining up. The current education system fails at producing workers with the right skills and employers are always complaining abou this.
What you are looking for is Khan Academy. Khan Academy with enough content, with sufficiently rigorous content, with sufficiently rigorous evaluation, to become accredited so that employers will value their assessment of a students worth. Actually, they would need to be better than merely being accredited, since employers sure aren't bending over backwards to pay accredited universities serious cash for access to their students.
See, what is Khan Academy really lacking at this point? Is the hard part their website with youtube hosted videos? Are they really just jonesing for some mobile developers? Or is producing quality content with broad coverage and depth their bottleneck?
Making an app is the easy part. Education is not failing for want of an app. Certainly not for want of a gamified app.
But hey, I can't stop you. Knock yourself out. Hell, pitch it to YC; I hear they are doing non-profits now.
1) The absolute last thing this world needs is more for-profit education, particularly for-profit education that has somebody else foot the bill. Do yourself a favor and try to sell this idea as non-profit; I was giving you the benefit of the doubt by assuming it was.
2) An app that teaches people things but doesn't have anything to teach them is worthless. Of course the software is the easy part...
If you really think a for-profit Khan Academy that teaches... nontraditional... curriculum, but doesn't actually have any content since you seem to be completely ignoring that problem... is what the world really needs, then pitch it to YC as a for-profit startup. I ain't stopping you...
Why would it need to be an app at all? It has zero benefits over being a website and requires students to buy an expensive piece of hardware to access it.
If you can show employers that your app truly tests useful abilities they would be lining up. The current education system fails at producing workers with the right skills and employers are always complaining abou this.