I can definitely see this tool being a promising bubble diagram or even automatic layout tool for architects/planners to implement.
At current stage, as many features are not available, I would suggest:
1) improve the UI and UX, for example display text/description for all bubbles instead of 'hover to display', make the bubbles interact with each other; make the tiny bubbles easier to select by adding different selection tools; make the dragging and releasing mouse more 'juicy'.
2) consider making multi-layered programming or 3D interface, as most of the space planning are happening in many floors of the building; or make a grouping feature to group certain bubbles together into different floors/areas, like a mindmap or what you could do at grasshopper.
3) There's a very recent beautiful game, achieving something many architects have been dreaming of, such as automatic planning and architectural feature creation. It may be a relevant inspiration this app. It's called Townscape, gameplay video can be found here.
Well done! Hope it helps and let's get into more conversation!