You're able to login to the cloudapps web interface fine, but upon clicking an application nothing happens.

By default Firefox Browser blocks the Citrix ICA plugin.

1) Open Firefox Add-on Settings:

2) Adjust the appropriate extension settings:

3) You can now close the Add-ons Manager tab, return to your Cloudapps web interface and launch your application. The settings take place immediately, there is no need to restart the browser.