Cad Assistant - Viewer / Converter
https://www.opencascade.com/content/cad-assistant
File Support: STEP, IGES, BREP, DXF, SAT (ACIS), glTF, JT, PLY, STL, OBJ, 3DM
Pros:
- free for personal / commercial use
- fast, light software
- easy to understand interface
- small files work well on android
- easy to add files to favorites for fast referencing
- edit model colors
Cons:
- large files don't load well on android, use STL's for faster model loading
- rotating view on android gets jerky with large files
- measuring tool is somewhat basic
Runs on:
- Windows
- OS X / macOS
- Apple iOS
- Android
Cad Assistant sample model