It allows you to focus on the logic of the app, because it manages well every aspect of the application: already-done components, routing, templating, DOM Manipulations.

I've been using Framework 7 for 6 months for developing Apache Cordova based mobile apps and for someone who comes from web development I think it's clearly the easiest and most fully featured framework to get started with. The strongest point of Framework 7 is definitely the learning curve which is almost non-existent in this case; if you have at least at least an intermediate knowledge of HTML, CSS and JavaScript (and maybe even jQuery) and don't have a lot of time to learn something new, this is most certainly the droid you're looking for. Thanks to the amazing official documentation filled with real-life examples ranging from basic to pretty advanced ones, you can put together an application UI in a couple of hours even just by copying, pasting and modifying code from the examples. Framework 7 boasts a strictly mobile optimized jQuery-like custom DOM library called Dom7 under the hood which is super easy to use if you've used jQuery before - it has almost exactly the same methods and features the same chaining capabilities. The framework performs quite well on lower-end devices too, but it really shines through on mid to high-end ones, especially if you're planning to take advantage of Cordova's pluggable webviews like Crosswalk or WKWebView.

The documentation would have to be my favorite part. Its difficult nowadays to really know what each framework's purpose is and how to use it. I also really enjoyed the animations. Smooth transitions mean a lot, if it even acts clunky, users will immediately be detracted from it. Keeping everything modular was also a plus, the fact that I can take out what I don't need and repurpose it for something else or even add more than what's required for future features is really nice.