dfndr vault is a free app to use, but subscribing to Premium will unlock additional features including: Unlimited Encrypted Cloud Backup, Fake PIN, Break-In Alerts, and App Camouflage.
The costs of a dfndr vault subscription to Premium are as follows:
1-month: $6.99 (US)/month
6-months: $4.66 (US)/month
12-months: $2.92 (US)/month