Free Mobile App Builder For WordPress

Hi,

I’m thinking of switching from joomla to wordpress for a radio site.
Looking through the plugins i noticed a few nice mobile app builders.
Are any of them free to use and which is the best of the bunch?

Hoping i can submit something for different mobile platforms.

Also, maybe i should start another topic but wondering if i’m making
my wp site mobile, available on different mobile devices, is their an
audio player that would work across different devices?
My site will host several Shoutcast radio channels and i find that
most of the html5 players seem to take a shoutcast URL.

Thanks in advance