I use this iphone app: http://www.shroomies.com/nutrition_menu/
It does allow you to use Flex points. You can choose to track old points, new points, calories, carbs or whatever. I'm, of course, doing momentum/flex, and the app makes it very easy. It has a food calculator, general food points list, extensive restaurant listings, activities (you can add custom ones), a favorites list (I love that!) and a place to track weight. It's a great little app.
The only thing it doesn't have a way to figure out how many points you should be eating in the first place. I found a website for that (there are several online), and I manually entered it in the app, so that's what it tracks.