Using the Renovation functionality in ArchiCAD you can export your BIM model highlighting the changes during the renovation.
In your 3D window in ArchiCAD choose a Renovation Filter and save a BIMx file
When you open the BIMx file on your mobile device you will see the 3D model as it appeared with the filter:
You can then continue doing this to save out the different stages as different BIMx models so your client can visualize the renovation process.
Read more about it here.