A handful of those eager to install the Windows Phone 8.1 preview just got an additional perk for being early adopters. NokiaNewsIreland has discovered an unannounced (and now unavailable) open beta for Twitter's Windows Phone 8.1 app that makes much better use of Microsoft's mobile OS than the regular client. For a start, it now ties into the Photos Hub -- it's now easy to browse the pictures you've tweeted, even if they didn't come from your phone.The test build also ties into your Me tile by launching Twitter when you want to post an update, and app-based sharing is once again functional. It even addresses a longstanding annoyance by jumping to your latest mentions rather than making you wade through past replies. Twitter hasn't said when the new features will reach the officially sanctioned release, but the apparently polished state of the beta suggests that Windows Phone owners may not have to wait much longer.