iOS 8.3 added a small optional tweak that allows you to bypass using your iCloud password when getting a free app, provided you don’t have Touch ID enabled for app store purchases and you don’t have restrictions enabled. To enable:
- Open your Settings app
- Tap iTunes & App Store
- Tap Password Settings
- If not already selected, choose whether you want your password required immediately or after 15 minutes (i.e., after you make a purchase, do you want to be able to make additional purchases for 15 minutes without having to re-enter your password?)
- Turn the switch off to “Require Password” for free downloads.
- Enter your iTunes password if prompted.
If you don’t see an option for Password Settings on step 3, you likely either have Touch ID enabled for purchases or you have restrictions turned on (Settings > General > Restrictions).