Not sure if this is out there or not and not sure why ios doesn't already have this feature because its dumb not to. Under the stock contacts app, you can click on groups and bring up all your different groups of contacts. My wife and I share our contacts and we both have work contacts. Therefore, I have 7 groups. I like to keep them well organized. Here is the problem - it is impossible to quickly determine which contacts are not added to a group (unless you download another app or have a Mac). So how hard would it be to add another group you can check off and call it 'ungrouped'? Then you can easily uncheck all the others and see which contacts don't belong to any group. Another nice feature would be to add the total number of contacts that are in the currently displayed list at the top of the Contacts list.
This seems like it should be easy. I would gladly pay money for this app if you could also add the functionality to then move these ungrouped contacts to one of the existing groups.
BTW, there is an app called iGroup Contacts that does all of this. However, it also tries to be the default program to open just about any filetype in iFile. For this reason, I can't stand having it installed. Please point me in the right direction if this is not what you do. Thanks!!