I’m using this plugin in my daily professional photography work and disagree with the @nesdam1981.
I prefer paying and knowing, that the tool, that became important for business, is supported and will be continued in future.
Yes, the tool does not allow changing galleries after sending it to the client, which is the only way to do it for a reliable proofing process. It’s a proofing and not a gallery plugin. Just understand what it all is about – in that niche it’s perfect. Less is more.