In order to use the K2BTools callyou, a key is required. When no key is used, the video call is automatically ended after thirty seconds.
To get a key you must send a mail to email@example.com sending the Android Package Name and Apple Bundle Identifier.
One license of CallYou allows to use the video call in three different applications. For this purpose three keys can be requested. If more keys are needed send a mail to firstname.lastname@example.org