If you are a Windows 8.1 user, you must be aware of the popular Twitter client called Tweetium. The developer behind the app has now created a Windows Phone version of the same app that is now available in beta in Windows Phone Store. If you have already bought Tweetium on Windows, you will not be charged when installing this app from the phone store.
Also, if you are a Tweetium Pro subscriber via the Windows app, then your Pro subscription carries over as well. Another great this about this client is that you Tweetium settings, read stats, etc will roam across all Windows devices.
Download it here from Windows Phone Store for $2.99.