3AM COFFEE SOFTWARE QTCoffee is a set of command-line tools. They are accessed by typing their name on the command-line. This is the way all command-line tools work. The documentation is installed as a set of man pages; there is also a Read Me and several other RTF documents whose locations are noted in the man pages.
The first sentence of the first panel of the installer tells you where they are installed. That panel also tells you how to get at the documentation.
We tried our best to help novices like you to find the application and its documentation by including this information in the installer, in the Read Me, and on our web site. We know of no better way of informing the user where a command-line tool goes. It's not like a GUI app where you just double click an icon. If you have a better idea, please email us.
(Version 1.2)