Wickr does not require a phone number. Wickr will affect neither your phone minutes nor SMS texts, but will affect data usage. This means Wickr may use your mobile data to send and receive if you are not using WiFi, a hotspot, or other unmetered (unlimited) data connection.
Wickr sends text messages, files, voice, and video as encrypted data, using your Wickr ID (Me) or email address (Pro) to correctly route from sender to receiver.
To prevent charges on your phone bill, most devices allow you to change how apps access your mobile data: