Defigo

Defigo is the simpler, smarter, safer way to access your building. If your door is served by our intercom, you can:
open it with the Defigo app, or the Defigo keyless tag;
answer the doorbell from your phone or tablet, receive a video of the guest, talk to them and let them in, wherever you are.
The Defigo app lets you update your profile and audio settings, and choose how you appear on the digital doorbell.

All you need to do is create a profile on Defigo, for free. For any questions about your door or your settings, talk to your building administrator.