Do the people I call need an OBi at their end for the calls to be free?
There are multiple ways that you can set-up the OBi so that calling is free. First, if the other person is using an OBi device OBi200 or OBi202, then a call to their nine-digit OBi number will be free. Other 'free' ways to call people involve calling from your OBi device or application 'through' another OBi by making a new call to the person you want to talk to. This second method requires you be in the OBi owner's Circle of Trust.
About the OBi
6001 America Center Dr
San Jose, CA 95002