Microsoft's new mobile phone operating system, Windows Phone 7 Series, isn't even publicly available, the developer code has only just been released and it is still only just finishing packing up from MIX10, but that hasn't stopped one developer already claiming that they've created the world's first officially announced Twitter app for Windows Phone 7 Series.

Although not the first, or the second for that matter - those claims goes to Microsoft who built one in 10 minutes live on stage at MIX10 and Seesmic for its Windows Phone 7 Series offering - the new app called Twikini is an evolution of a Windows Mobile 6.5 app which goes by the same name.

"Like the current version for WM 6.x, we plan on making Twikini the fastest, best-designed and most feature-packed Twitter client available for 7, and expect it to be released in time for launch" claim developers Mist Labs and Trinket Software.

It might not be able to do copy/paste, multitasking, or take memory cards, but at least those worried that they wouldn't be able to tweet from the new Microsoft powered smartphones, that are due out later this year, will be able to sleep tight from now on.