Website to App HTML to iOS and Android

I've been asked to turn a existing responsive website to an app, for both apple and android marketplaces. Apparently this is so that it can be accessed without an internet connection.

I'm unsure as to where to start so I would appreciate someone pointing me in the right direction.

I have no experience of knowledge of Objective-c or Java to create anything from scratch. I've seen a few programs to make the process easier and even websites promising to convert a website into an app for a one off fee/monthly payment.

Alternatively i've seen an article on using HTML appcache to make website available offline.

Thank you.