Just in case you haven't seen it yet, Zurb just released a "Foundation for Apps" framework. Its the same Zurb you know and love, but they've tweaked out even more to be more mobile app friendly and are using AngularJS on the backend to get things going. I'm working on rebuilding a project of mine now to use it. Their CLI tool seems a little buggy for the moment, but if you use the standard node/bower/bundler install route, you should be okay.
From what I've seen, both are using a 12 column infrastructure, but class naming is different. Zurb likes a friendlier naming convention, such as class="small twelve columns" where bootstrap goes with something like "sm-12-col". I know bootstrap has more components, but a lot of them are similar. Be interested to dig deeper (or google an article) on the transition.
I like it! I spent quite a lot of time testing various off-canvas navigation options. This would have saved me a lot of time. I don't think I'll be replacing Bootstrap here on Hawkee any time soon, but I may consider Foundation for future projects.