How do I disable a password for already purchased apps
Have you tried Settings > iTunes &amp; App Stores > Password Settings. 

Under Purchases and In-App Purchases you'll have the option of either always requiring the password or to require it after 15 mins. (That is, you enter the password in once and for the next 15mins you won't be asked again).

Below those options you also have the Free Downloads setting where you can choose not to require a password at all for free downloads.

NOTE: If you don't see the password settings mentioned above, then you've got Touch ID turned on for purchases, in which case these settings aren't avaiable. To change this go to Settings > Touch ID &amp; Passcode.