I installed the All in One Security and Firewall plugin on my self-hosted WordPress blog site. Setup was easy, but I ran into one snag - enabling the Pingback Protection will prevent the WordPress iOS app from logging in. It kept saying there was a problem with my WordPress setup. After a quick Google search, I saw some references to the XMLRPC file either being missing or locked, which would prevent the iOS app from working. Sure enough, as soon as I disabled the Pingback Protection, the app now works again.
There may not be a way to protect the file and still allow the app to work, but maybe a warning in the plugin to let people know that the two are related?
Thanks for a great app!