Besides Unity Webapps, Fogger is a good alternative to turns your web apps into regular desktop apps on Ubuntu or Linux Mint.
Fogger acts as a bridge between web applications and the linux desktop. It exposes an easy to use JS API to webapps which can be used to interact with the host desktop environment. It can also be used to write basic desktop apps for linux in pure web style.
This tutorial will show you how to install Fogger in Ubuntu 13.10, Ubuntu 13.04, Ubuntu 12.04, Ubuntu 11.10 and Linux Mint via PPA.
To get started, press Ctrl+Alt+T to open terminal. When it opens, run commands to add PPA:
sudo add-apt-repository ppa:loneowais/fogger
After that, run commands to update package lists and install Fogger:
sudo apt-get update; sudo apt-get install fogger