Desura is a great application (and service) especially for those who likes indie games. It's available on Windows and Linux. By using Desura, you can browse, search, buy (there are many free games though), and install games on your computer. It also helps you to manage, update, and even install new mods easily. Just install and play!
Install Desura on Ubuntu
Installing Desura on Ubuntu/Linux is a piece of cake. Simply, download the installer here, extract the archive, and run the Desura file. The installer will start download necessary files from its server. Once completed, you can login or create new account for Desura.
Once logged in, you will be able to browse, search, and install many available games. At every page of game, you can watch the trailer video, view the rating, read review and comments of other users. If you are interested in giving the game a try, just click "Install game" to install (or buy) the game.
Enjoy :)