Did you know that in Ubuntu (and derivates), to install a package by its name, you can simply press Alt + F2, then enter:

apt:PACKAGE_NAME

where PACKAGE_NAME is the name of the package you want to install (firefox, smplayer or whatever)? I know it's pretty obvious, but I didn't think about it.

Thanks to UniLab for pointing this out.

This is possible through the apturl package which can be used to install application by simply clicking on a apt:// url on a website.

Apturl should be installed by default, but in case it isn't, run this in a terminal:

sudo apt-get install apturl