I struggled to determine the correct ftp settings for the Webplus app. Unfortunately, Plusnet support couldnt offer any help with this. Understandable, I think, since there are so may website apps out there.
In case anyone else is using this software, here are example settings to use. The key is to use the correct folder name - htdocs. which is mandatory for Plusnet webspace.
So far, I have found the functionality and ease of use in this app is very impressive.