"It's also now possible to turn on a setting to allow you to download free apps without the need to enter your password. We have a full list of the changes in iOS 8.3 in our iOS 8 Features Roundup."
and
https://www.macrumors.com/2015/03/23/ios-8-3-new-password-siri-features/
In the Settings menu of an iOS device running iOS 8.3 beta 3, there's a new option under iTunes & App Store labeled "Password Settings." In this section, there is an option to change the password settings for purchases and in-app purchases, choosing options to either "Always Require" a password when making a purchase, or to "Require After 15 Minutes."
"Always Require" and "Require After 15 Minutes" are not new settings -- the options have previously been located within the Restrictions section of the Settings app -- but a user is required to select one in order to access a new password toggle setting, which lets users toggle the password requirement for free apps on and off. When toggled on, downloads labeled as "GET" in the App Store will not require a password.
I don't see mine! maybe it was removed MR? Unless i'm looking in the wrong place. Settings>iTunes & App store. No password option.