M2mhub is a simple web-based interface to the M2M databse. Though it is not a turn-key application, I would be interested in collaborating with others to make it more useful. Let me know if you're writing custom reports with Made2Manage and have any interest in sharing.
This code is currently under regular development. However, having no collaborators, I'm not inspired to maintain a lot of documentation. To get a dated overview of what I'm doing, check out http://youtu.be/4nLrlibrZPA. A lot has changed since then, so if you have any questions, just contact me via github.