Ben Brooks makes a suggestion regarding iOS App Store purchasing:
My proposal: if a user has a passcode set to activate no longer than 15 minutes of inactivity (I believe this is the current memory of the App Store for password-less purchases) then allow the user to turn on a feature where you can buy anything password-less once the device has been unlocked with the passcode.
One of the things Brooks’ is exceptionally good at is coming up with simple solutions without overcomplicating things. But my biggest gripe with the password entry revolves around the fact that you have to enter it for every upgrade as well, upgrades that are free.
In my opinion, most people’s gripes would be solved just by removing the need to enter it for upgrades. I like the confirmation when I am spending money, but it seems silly when I am not.