facebook app needs SSL = me clueless

so im linking my wordpress blog to one of my facebook apps i created (those tiles that sit on the top right under your cover image) on my facebook fan page. basically when people click on that facebook opens an iframe in itself to the webpage you linked.

each link needs to be SSL certified. its just a photography blog im linking those apps to.

i downloaded this plugin thinking that would solve my SSL needs but its just a plugin that manages it. https://www.ads-software.com/extend/plugins/wordpress-https/

im looking into purchasing rapidssl as its the cheapest unless there is another work around to getting this to work. but after purchasing im not sure what to do as i dont want to break my site since im pretty html/code/etc illiterate. any insight? thanks!