For extra security, the app may be configured to ask for a password on activation. This password is the same as the one used for encryption, so you have to create an encryption key first if you haven't already done that. Then, the “Require password” checkbox will be accessible and you may select it.

If you forget the password, you can always clear the app data in Android Settings and start using the app from scratch. However, all recordings encrypted using the key generated with this password will be irreversibly lost.