In the Web version of iGap you are not only able to create channel in private or public but also you can convert and change channel type. If you want to change the channel type from public to private, do not forget that your channel will not need any ID or Username any more.
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.
Android version of iGap has a feature to create channels in private or public. You can create channels and add members or they join themselves in order to benefit the shared media by you. It helps you to share any files or news you like to with anyone whether you wanted to add or s/he added by the link.