The SketchUp Mobile Viewer is exactly that, but due to the complexity of the SketchUp models it will only display models which have already been processed in the 3D Warehouse. Note that the 3D Warehouse is not a “store” but actually a storage repository. The intent is that you upload models that you’ve created to the 3D Warehouse (which you can keep private if you wish) and then log into the SketchUp Mobile Viewer with your login data so that you can easily download your models to your tablet for sharing with clients.
Secondary to the 3D Warehouse discussion, please be sure you’re only using SKP files as the SKB is a backup file and if you use that as your edited file type you are going to get erratic and undesired results in your backups if you ever need them. My recommendation is to NEVER associate the SKB file extension with SketchUp directly.