General Users:

1. Trouble with Firefox? Launch it in safe mode with FireLauncher with a mouse click.
2. Easily create separate profiles for different users of your computer. Allow them easy access from a single menu.
3. Easily create separate profiles for your own different uses. Run them concurrently from a single menu.
4. Browser takes too much time to start?
   You can have a no-frills default profile for when you want to quickly open something, a profile for your blogging activities with requisite extensions installed, and so on.
5. Usually it's a bit of work to maintain multiple profiles and use them concurrently. Having a single menu in your system tray or Start Menu to do that makes life much easier.
6. Install a Theme or extension globally for all users.
7. Launch trouble-shooting sessions through a single GUI without typing anything.
8. Explore what command line options are available for a Mozilla family application you have installed.

Extension Developers:

1. Easily create and launch different testing profiles.
2. Spare yourself the hassle of creating desktop shortcuts with options like –console , -jsconsole etc.
3. Launch all your chrome URIs from a single menu.
4. Leverage this application's ease of use to add support for any other application by directly editing the XML files.

Or Maybe Just:

1. Know these words— safe-mode , profilemanager,no-remote ?
   Then FireLauncher is a program you should look into.
2. Reached the coming of age as a Firefox/Thunderbird user and someone has just mentioned multiple profiles and safe mode to you?
   Maybe it's time for FireLauncher too.