Developers BC3 has released their new app – Upload to Youtube, which does exactly what is says on the tin.
The app is designed and will only work on Windows Phone 8.1, and lets you pick videos not just from your camera roll, but using a file picker from anywhere on your phone (such as the Downloads folder for example).
The app will also accept input via the Share menu, allowing you for example to craft a video in Movie Maker and, in theory, use the Share menu to upload it to YouTube. In practice this is not widely supported yet, but should work from most new file explorers without issue, including Microsoft’s own Files app.
The app has two big weaknesses – one simple to rectify and another which will probably take some work.
The first is the user interface, which uses a light grey font which suggests on-screen buttons are actually “greyed out” and inactive when they are actually perfectly selectable.
Windows Phone 8.1 does in fact support background uploads, so this may be a feature which is still on the way.
The app is free and can be downloaded from the Windows Phone Store here.