I'm currently surveying 600 of my early users of my android app.

What's disconcerting so far is their answer to the following question:

The app will be 100% free for you forever (thank you for the support) however what do you think is reasonable pricing? Consider, that some of the revenue will be re-invested in making the app better for all users

It's early days now but it's trending towards $1/$2 when in reality I believe that it's worth allot more to anyone who gets a fair amount of value from it.