These websites allow you to browser the valid RPKI announcements. They show which address ranges are covered by RPKI and who the issuing authority is.
Website which tests, if your provider filters invalid annoucements using RPKI.
Ziggy is a tool to inspect the RPKI ecosystem at arbitrary points in the past. It is developed by NlNetLabs. More details abouut the ziggy tool can be found in the announcement blogpost.