It’s been some time since dojox/storage, and a lot of things changed since then. Most notably: Browsers now have IndexedDB, and Dojo now has the dojo/store API that widgets can directly work with.
The dojo/store API was built with IndexedDB and offline in mind, has a nice API and allows asynchronism, meaning that it can return Promises instead of values. The only thing missing was a persistence layer that would take data via that API and store it in the user’s browser, e.g. for offline availability.
And that’s what Storehouse is: A persistent object store implementing the dojo/store API.