Framework7 - is a free and open source mobile HTML framework to develop hybrid mobile apps or web apps with iOS & Android native look and feel. It is also an indispensable prototyping apps tool to show working app prototype as soon as possible in case you need to.
Framework7 is not compatible with all platforms. It is focused only on iOS and Google Material design to bring the best experience and simplicity.
Framework7 is definitely for you if you decide to build iOS or Android hybrid app (PhoneGap) or web app that looks like and feels as great native iOS and Google Material apps.