In August of 2007, I spent a couple weeks planning (and writing some now-deleted blog posts for) my own Mac Twitter client, to be called Twinkle.
One of its primary features would have been what I then called a “HUD-like” UI that would allow you to traverse Twitter relationships quickly.
Want to see the followers of a tweet’s author? Select the tweet, click a button (or press a keystroke combination, etc.), and a custom-UI list pops up over your window. Want to see who’s following someone on that list? Hover over the list entry, and a new HUD list would pop up next to it. Rinse and repeat, possibly until half your screen is filled. Once you’ve found someone interesting, select that person, and then your main window contents change.
It would be like nested menus, but…better. With regular nested menus, it’s easy to accidentally click or hover somewhere that makes the nested structure you painstakingly navigated disappear. So I’d have to put in a lot of little behaviorial details to minimize that — similar to, but moreso than, the Mac mouse-over-empty-space menu behavior that you only miss once it’s gone. Also, I’d probably add a widget to bring back your previous navigation, in case you click somewhere else by mistake, or you just want to keep exploring.
It seems to me that such a UI could never work on the iPhone, where you dole out information in screen-sized morsels, or not at all.
Could it work on the iPad? I’ve heard of popovers, but I haven’t investigated the iPad SDK much yet.
Will this be my next project? No. The world has enough Twitter clients. But I’ve been interested in custom navigation for a while now; it’s one of the things I’ll be talking about here.