We have posted an updated plugin development guide at : https://www.sitestorepro.com/download_content/SIteStorePro_Plugin_Developer_Guide.pdf The updated guide contains instructions on integrating additional features into payment processor plugins such as processor initialization file loading, required JavaScript loaders and embedded billing forms. The Site Store Pro Developer Plugin Guide 2.0 also includes a section that details a new plugin category called "tools". The "tools" plugin category gives you the ability to create site and admin utilities for management functions such as data backups, auto responder emails and custom reports/data queries. If you need assistance creating your custom plugin and/or would like a quote for us to create a custom plugin for your Site Store Pro or WPCartPro site, please contact us at [email protected]