What exactly will I get when I unlock all features?

Usage of the Voicemail and Texting features is free of charge.

Scheduling a call or creating a video is also free, you can request an unlimited amount of calls and videos free of charge.

If you want to make the received calls or videos more personal, you can choose to activate more personalisation options by upgrading to Premium:

Santa says your child’s name
Over 6000 names are already available and will be said by Santa several times during the call or in the video messages. If the name you need is not there, it can be recorded for you by Santa at no additional charge. Please take into account that it could take several days for the recording to become available in the app. Be sure to request your recording on time for Christmas.
Santa knows what your child likes
Choose from a variety of hobbies, sports, food and activities to further personalize the call. Santa will briefly mention one of your child's interests during the call.

Additionally, the following useful features for parents are also unlocked:

Record your child during calls from Santa and while calling his voicemail
Listen back to the messages which you're child left for Santa on his voicemail, or listen how your child reacted when Santa told them they were on the nice list.
Video messages which you created also are stored in your account
You get discounted pricing on the "Welcome to the North Pole" family video
Passcode for Settings
You can protect the Settings screen with a passcode, so that only you can access it.
Black screen after scheduled call
After a received call, instead of going back to the main menu, the screen will go to black for 10 seconds. Recommended for parents of children that can read to use this time to calmly take back the phone and close the app.
Child safe main menu
Hides the “Schedule a Call” button from the main menu, so your child can use the Voicemail and Texting features without getting suspicious. "Schedule a Call" can then only be reached from the Settings screen.