[rodriguezcommaj]

I have used both extensively on both personal and work-related projects. Both are great, but Foundation gets my vote as it is lighter and much easier to work with as a designer. With Bootstrap, you are pretty much stuck with that general look unless you want to do A LOT of work. You will end up looking like every other app out there using it.

With Foundation, it is much easier to override their styling and build something that is unique. You feel more like you are working WITH a framework, as opposed to working AGAINST one - which is how I feel using Bootstrap.

Either way, you can't go wrong, but if you value saving time by not overriding a million CSS rules when designing your site - go with Foundation.