a few weeks ago, WhatsApp updated their iOS app with a new URL Scheme, multiple photo uploads, iCloud backup feature and the app is now free with a yearly subscription.

Federico Viticci posted a nice tutorial on using the new URL Scheme, I suggest you check it out.

I suggest checking out The Prompt podcast episodes 1 and 2 by Federico Viticci, Myke Hurley and Stephen Hackett, Where they discuss WWDC 2013, iOS 7, Timer Coalescing and other recent Apple news. It's really great, and if would like a preview, you could find it inside this post.