KiddaC As most will agree this is a great app. So apologies for making this suggestion
I know having a "favourites" section for the Series isn't currently possible. And this really is the only thing that is missing.
So what about a "Recent Search" folder instead that just remembers your recent searches? In this folder then you could have the option to select one of our recent searches which would do a search in the "ALL" category and bring you to the search results. This way you could find your Series quite quickly without having to type it into the search over and over.
An option then to remove listings from this folder would be handy (for when you are finished watching a particualar series).
Thanks.