Is any visualisation App for iPAD that can import IGS or/and STEP files ?
GrabCAD has an app for both iOS and Android! We released our Android app yesterday and will continue to develop tools that help you get your work done.
Get the Android app: https://play.google.com/store/apps/details?id=com.grabcad
Get the iPad and iPhone apps: https://itunes.apple.com/gb/app/grabcad/id518400211
There is also CAD Assistant - free offline 3D viewer and convertor supporting STEP/IGES/BREP as well as STL/OBJ/PLY files.
For Android: https://play.google.com/store/apps/details?id=org.opencascade.cadassistant
For iPad: https://itunes.apple.com/ai/app/cad-assistant/id984561628
For Windows/OS X: https://www.opencascade.com/content/cad-assistant
Our new MyCadbox app can open STEP files directly from Dropbox or email attachment on iPad. Another option is to use MyCadbox desktop app which will sync STEP files and markups automatically between your PC and iPad. It's free.