Can "forward to friends" apply for landing page other than emailer?

What do you mean exactly? There is no Forward to Friend feature for LPs...

But you could setup a flow that would do this:

1. Person A fills out form A that asks Person B to come visit the site
2. flow sends Person B an email inviting them to an LP.
3. Person B visits the page.

Hi Josh,

Thank you for your reply.  I am not quite sure what exactly your adviced flow goes?  I double if it is an automatic email reply for anyone who filled out a form?  

Thanks,
Cindia