After all, thanks for this usefull plugin.
I just want to submit to you an important install issue:
When i do an install throw the WP Plugins panel, a plugin directory is created with the name: accessible-helper! So, the plugin didn't work!
Cause, in your install doc and files inclusion, you refer to the name: accessible_helper
So, i simply fixed it, by renaming the plugin directory to 'accessible_helper', but i hope you will fix it too, in the repo version.
Another thing: when i click on the link 'Manage Error Messages' in the plugin option page, i got a blank page with a message that said it can't load accessibility (in french: 'Impossible de charger accessibility'). I don't know if it's normal or it's an issue or i do something wrong.
Thanks and excuse me for my poor english.