The Ping iApp is an amazing piece of golf putting software that Apple say is one of the best uses of the iPhone they have seen so far. It's free which is good, but the cost of the cradle seems a bit high. A couple of heavy duty rubber bands will do the job of holding the iPhone on the shaft, but probably not as well.

As a fitting device it is another great tool and together with the adjustable Ping putter you should be able to get a Ping putter that matches your stroke and gives you more consistency and really that is what this app helps you identify.

There is lots of great information on stroke path, impact angle and tempo but it is really the consistency figure that you should focus on. Having an open or closed face at impact is not to big a deal as long as your stroke is consistent so that you hole more putts.

Better putters may find that they are equally as consistent with a face-balanced, slight arc or strong arc putter and therefore the app takes on more of a practice aid to help get that consistency with whatever putter you like the look of. Getting that putter adjusted for length and lie is really more important and that may in turn affect your stroke path.

If you are starting out in golf, or struggle with your putting, then I would suggest using the iPing putting app to find your stroke path, then try out putters than match that and then get it adjusted for length and lie and try the app again.

If I had to be picky then some way of recording your success of holing the 5 putts in the test would be good feedback to help you adjust your stroke or putter to get the optimum set up for you as holing putts is really what golf is about. Custom fitting is never black and white and that applies especially to putters as they are so much personal preference. However the iPing app is a great tool for fitting and extremely addictive for practice.