This Lattice Structures Visualizer is useful to see simple cubic, body-centered cubic, face-centered cubic, NaCl, CaF2, and hcp lattice structures. You can add atoms/ions layer by layer, break them apart into individual unit cells, and perform other modifications to better observe the structures without physical models. I use this routinely in my general and inorganic chemistry classes.
I have used this in remote teaching of solids for general chemistry students, and I offer it as a resource for my upper level courses. I show them some of the features and allow them to explore on their own.
Specifically, I ask students to investigate the Layer [by layer] building with the Expansion tool with rotation as necessary. I have them compare the Single setup that shows 100% of all atoms both fully and partially in the unit cell with the Unit Cell tool. The students seem to find the Expansion tool with the Unit Cell view most informative of how the pieces all fit together and how a lattice is built.
I have first year students look at and examine simple cubic, body-centered cubic, and face-centered cubic structures. ABA and ABC layering for FCC and HCP are both clearly shown with colors. I mention the structures and briefly show them some features, but they are outside of the focus.
For inorganic students, the Layering effectively shows the interlocking FCC structures for sodium and chloride ions, and the Coordination feature clearly displays the filling of octahedral holes. CaF2 shows tetrahedral holes well.
I use no formal evaluation with this tool.
When possible, I use this website in conjunction with physical models of SC, BCC, and FCC structures made of small plastic spheres that have been glued together. These physical models work fairly well, but some students always struggle with atoms shared between unit cells. They can see the partial or shared atoms much more clearly when they use the Unit Cell and Expansion tools from this website.