NWD files, IPT files, ASM (1st level) and IDW files are all viewable on mobile, but STEP files are not currently viewable on Mobile. Perhaps that would be something worthwhile for some of us. Having 3D viewing capabilities of STEP files on Mobile would simplify the steps needed to provide access to models, without having to go through the steps like adding the file into Navis or import into inventor and re-upload to Docs.