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Meshroom, as suggested by others. If you do this, I think you'd do well to spend a little time setting up a little "studio" for it. A rotating plate, e.g. a vinyl player to place the items on, plus even lighting, would help a lot. If possible, two cameras on tripod at different heights would be good.

You can do it handheld for sure, just make sure to have plenty of light and put the items on a small pedestal so you can get low angles of them without a table getting in the way. But for several hundred objects, it's going to take a while.

Yeah, Meshroom! https://github.com/alicevision/meshroom

There are plenty of 3d scanning apps for phones. I don't know which one to recommend but at a glance this one looks nice

https://www.qlone.pro/