Yes, I worked on that project. It is currently targeted at large clients who have their own MS SQL server teams (thus the price). It's a fairly young product.
It consists of two installers, one for the Revit add-in and one for a Windows WCF service. The Revit add-in extracts (potentially LOTS of) data from a Revit project and sends it to the Windows service. The add-in lets you filter out things in which you're not interested (e.g. by category, view, level, etc.) so you can fine tune what data is extracted, to speed up extraction time and reduce the amount of data that would need to be stored in SQL server. It uses the same data snapshotting engine that our "Model Compare" tool uses.
The Windows Service will then write the data to a Microsoft SQL Server database to which the client points it. We provide a highly normalized blank database which consists of the required schema (some 60 or so tables, I think) which represent our best guess at what the underlying Revit database structure might look like (for those things we go after). It focuses on the "I" in BIM, so it does not pull things like geometric information, but does pull information about families, types, instances, parameters, schedules, groups and more.
Yes, multiple data "snapshots" from multiple projects can all get stored into a single database, which can then have queries written by the client's SQL team to compare data over time for one project, or compare data between any number of projects, or some combination of both.
Currently there isn't any cloud-based support per se, but it wouldn't be difficult to extend the service to support hosting it offsite. Currently the service only pushes data into MS SQL server, so it's up to the client to *use* that data in whatever manner they see fit. So the client themselves would have to write a cloud-based app to consume the data for use on mobile devices.
It's focus is to simply extract data and push it into a SQL database and let the client do with it what they will. Nothing more. We experimented for a while with trying to create "stock" reports, but every client we talked to wanted something different, so we chose to keep it simpler.
The add-in can also extract the data to a (.NET DataSet) XML file. We could probably add JSON file support fairly easily, I think.
I'm vaguely aware of FireRatingCloud, and haven't heard of the CompHound component tracker before. I'll have to check that out.