Adding a tip-a-friend to a page
I've assumed that we don't want tip-a-friend links on every page (it's possible to configure it to do this) so to add a tip-a-friend link, you need to add the flexible content element named "fce_tipafriend".
Check out the interesting page for the example. If you want the link to look different, you can style it; it's an FCE, after all :)
Modifying the template
You'll need to modify the template file for this extension, specifically for the mail that gets sent, and the confirmation message that the mail has been sent.
The template file in use is: EXT:tipafriend_plus/pi1/current.tmpl