Read and change your data on all facebook.com sites
To run the Ponyhoof magic on Facebook itself.
Read and change your data on all little.my sites
Allows the installer page to detect the presence of Ponyhoof and offers to update instead.
Read and change your data on all messenger.com sites
Facebook offers a separate website that only shows Messenger to reduce clutter. You can enable/disable Ponyhoof from running on messenger.com at Ponyhoof Options > Misc > Run Ponyhoof on Messenger.com.