I realized earlier last week that LifeStat is just a particular combination of services that could communicate with Double-X's central infrastructure. Specifically, it is two different views on time-series data (a calendar view and a cross-correlation view) and an extension that would allow over-the-network merging of files. Designing the right architecture for Double-X's backbone would allow LifeStat to just be a particular configuration of Double-X.
That said, if Double-X were extremely configurable, then it would be good to have an app that wires together the backbone and services to produce custom solutions so that end-users (for whom the full power of Double-X may be irrelevant) are presented with exactly and only what they want to see in their situation. The limit as x goes to infinity is that we program the backbone and relevant services AND pre-package them together to provide solutions for the end-user without the end-user being at all aware that they are using a specialized form of a much more general package.