We’re currently working on an update that will do this automatically, so that all your devices are in sync. This will be released in a Ribbet update soon.
In the meantime, you can manually do this by logging into ribbet.com from your phone (from the top right 3 bar menu) and choosing “My Library” (from this same menu). From there you can upload photos from your phone to your Ribbet account and also download your Ribbet History and Uploads to your phone.
Please let us know if you have any other questions!