FaceNames Free - Ideas

I'm trying to decide what a free version of FaceNames should look like. It needs to show the feature set but not be so complete that it the end user will avoid buying the full version.

Some ideas:

• Don't save the scores between sessions, but otherwise fully functional. Pro: User gets a good experience of the app for free. Con: It might be enough functionality that the user doesn't need to upgrade. Possible out: Add other features to the paid version, such as a timed quiz mode, and do not put these new features into the free version.
• Remove scoring completely - between uses and during use. Pro: ? Con: User only gets a partial feel for how the app works during a regular session -- instead of showing less well known people more often, it will show them people randomly.
• Limit the number of people that are added to FaceNames. Pro: Hmmm, not sure; no pro for the user, certainly. Con: This is a feature limited version of the app and I'm not sure Apple would approve it. 

Well, the best approach seems to be the first - to not save scores between sessions. Perhaps that's what I'll roll with - and differentiate the paid version from the free by add new features to the paid version as quickly as I can.