How to move flatpress to SSL

Apart from all the Virtual Hosting and SSL certificates, you have probably found that it keeps redirecting you to the HTTP version.
What you need to change is the defaults.php file.

Change:

define('BLOG_BASEURL', 'http://'.$_SERVER['HTTP_HOST']. BLOG_ROOT);

to:

define('BLOG_BASEURL', 'https://'.$_SERVER['HTTP_HOST']. BLOG_ROOT);

and that should do it!