Tokaido will likely feature a Springboard/Spatial app list, optimized for working on a single app in a single window. You can, of course, open multiple windows.
We've shied away from a source-view approach for the application / details...
A hub for all important information about the app you're working on.
Tōkaidō's notifications UI will show high-priority items like errors and exceptions, as well as codebase-health alerts like outdated gems or plugins.