In the Web version of iGap there are many features as in other versions. One of the most important of them is to have your own room as a channel and even in public. It means that you do not need to add members to increase the number, all iGap users can join it easily and use the shared media. Do not forget, your public channel needs a username or an ID, so others can join it by clicking.
In iGap through Web version, there is this feature to create new channels. Channels are as Public or Private. In private one you decide who to be added to your channel but in public every one of iGap users can join it and enjoy the shared media. So, try to make your decision about your channel type first and then make use of it.