Building whatsapp-like interface around Chat+

I like Chat+ and its features, for now it is great on my website, but I need something similar to Whatsapp's interface for my users to use on their mobile devices. 

Please note, I am not looking for something as powerful as Whatsapp, but I like its friendly GUI interface and as long as my members can share txt, photos and videos via Chat+ Mod, that would suffice for now..

Looking for a developer who is familiar with Mobile Apps development - Please note, we are not building a new App, as you know, Chat+ is already mobile compatible & has everything needed for this project, but I am simply looking to build a nice GUI interface around it..

FYI - Someone has already built similar App around Chat+ which you can see at:
https://conversations.im/   Therefore, the code is already out there to help with this project.

Thanks.