Swift Performance fully supports Cloudflare. The only thing what you need is enable autopurge and configure Cloudflare API credentials.
Once you configured Cloudflare, Swift Performance will be able to purge Cloudflare cache when it is necessary. With this you can use Cloudflare APO, or Proxy Caching (Proxy caching is a free solution to get the power of Cloudflare APO) without any other plugin.
Cloudflare Account E-mail
This is the e-mail address what you are using for your Cloudflare account.
Cloudflare API Key
You can use either Global API key, or create a custom key to authenticate your site
This is always your top level domain, without any subdomain (for example without www), even if your site is hosted on subdomain or www version of your domain.