- I think the mobile detection thing uses nothing but window size to determine if this is on a mobile browser or a desktop, so it mistakes my (definitely desktop) browser window for a mobile one. I know from my friends who do frontend stuff that reliably detecting a mobile browser isn't very straightforward (or even possible?) but perhaps a "my device was not correctly detected, request desktop site" button would help? Or at least a hint about resizing the browser window for technical users who are, nonetheless, not very web-inclined?
- The plural of "scenario" is "scenarios", without an apostrophe. Also frames, not frame's. Sorry if it seems overly pedantic but I see a lot of people (including native speakers) do this and it's driving me nuts.
Other than that I think like the idea! Me and web interfaces don't really get along so I can't say I've done too much test driving but I realize that's a personal preference of mine, and quite possibly something that puts me outside your target audience. I don't suppose there's yet a good web equivalent of Visio, and I'm fairly sure that the ones I've tried don't have the hierarchical/structured approach to diagramming that Terrastruct has. Best of luck with it -- I hope ten years from now I can tell my friends I went all grammar nazi on alixanderwang, world-renowned billionaire and the founder of Terrastruct!