Update from Shapr3d team:
We have just released the new 3d alignment tool feature with the 3.52 app version
This will allow you to simply tap on the body faces to get them snapped together.
Simply update the app and please share your feedback with us.
Here are more details about the feature:
Being used to assemblies in Solidworks the feature I miss most in Shapr3D is an align function. Just being able to select faces instead of only points with the translate tool would be a great improvement, but a step further would be if bodies had their own planes that could be used with the translate tool. If bodies had an x,y,z plane by default and could contain additional planes derived from default planes most alignment issues would be dealt with.