Lumiya Viewer only transmits your Second Life login details to the Second Life grid service, strictly for the purpose of logging in to the grid. Your password is being transmiited in an encrypted form which is not easily decrypted, and is never sent or stored in clear text.
Lumiya Viewer never transmits your Second Life login details to any person or organization other than the Second Life grid service.
To make logging in more convenient for you, Lumiya viewer may optionally store your Second Life login details on your phone. Your password will not be stored unless you have instructed the viewer to do so, by enabling "Save password" option. In that case, your password is stored in an encrypted form, which is not easily decrypted.
Lumiya Viewer does not collect any usage statistics or any of your personal data.
Lumiya Viewer does not connect to any other websites or services other than Second Life grid service, except for the purposes of playing streaming audio which is provided by servers external to Second Life. Before it does so, Lumiya asks you for explicit permission to connect to the given streaming audio service. No sensitive information is provided to the streaming audio services; however, if you do not trust given streaming audio service at all, you can choose not to use it.
Like most web sites, our server software keeps logs of all connections to the server, including the IP address of incoming connections. Your IP address does not identify you personally, and is not associated with your user name or other details about you.