I've ported over my app from Windows Phone 7/8, but now I've found myself at a loss of functionality without your textboxes available as universal controls. RadTextBox, RadPasswordBox, and RadNumericUpDown are all controls that would be fantastic if they could be ported over to Universal. Thanks!
Make RadDiagnostics Universal control.
Port ConversationView to Windows Universal
Please add an optional placeholder text for the RadAutoCompleteBox that is shown in a light style and disappears when the control gets focus / has content. This feature seems to be available for the RadAutoCompleteBox for HTML, but is missing for the C# / Windows Universal version.