I will be honest, I'm not so sure about the value of the Gun application. Google claims that they are offering free access to a simple and intuitive GPS software solution, in order to encourage developers to build apps for Android. But is the Gun application worth the money? Is it worth the purchase price?
I'm not sure. Google has invested a lot into Android in order to get it to where it is today. I think that it would be fair to say that their efforts will benefit the entire Android platform as well. If this particular application was truly intended to be built for Android, then I don't think that it would be worth the cost. However, it is free and in the Google Play Store. They can't require developers to pay for this. So, while I don't like the Gun application, it is not the killer app that Google might have hoped for when it launched the Android platform.
In short, while it might be true that the Gun application is free, I think that it's still too soon to tell whether or not the Android platform will benefit from the development of such an application. So far, I haven't seen any in-depth Android reviews that are very positive about the Gun application. In fact, it seems to me like Android is more for the developer than for the consumers. Hopefully, they will change their approach with time.