The Fiji Packager allows you to bundle an existing Fiji installation so you can share all the plugins and update sites with colleagues. It makes a single archive (.zip, .tar.gz, .tar.bz2 are supported at the moment) from the files in Fiji.app/.
After clicking on Plugins › Utilities › Make Fiji Package (note: there are two Plugins › Utilities menus because ImageJ1 enforces separate submenus for non-core plugins which makes things a little bit confusing), you will be asked for the format and the file name.
After both are specified, the plugin does all the rest, reporting its progress in the status bar.
Files included in the archive
The packager includes files from the following subdirectories of Fiji.app/:
It also includes the ImageJ launcher and the updater database including the current list of update sites.