Best 'asset' to snap other prefabs together.

Hello! So I used a earlier version of Unity and recently updated to the most recent one and I noticed that one of the assets I used (Easy Map Builder) is no longer in the asset store, and it does not work with the newer Unity.

It was a add-on that I really enjoyed, it made snapping wall, floor and roof prefabs together really handy. As well as other own made objects and objects. I am self learned in Unity and perhaps not that good so it might be something I am missing, but is there any other asset that can do the same job as 'Easy Map Builder' did?

Or is there perhaps any other way of building prefabs together without buying or using such a asset?

Thanks!