If it is a real anamorphic lens I assume you will need to digitally stretch the resulting images horizontally. In my admittedly brief skim of your link I saw no mention of it.
Edit: found the same lens on Amazon, read some reviews. Yep, it's the real glass. Images need to be stretched to 'normalize". One reviewer: "Yes you’ll need the moment app to desqueeze the image." (Of course can probably do the same in any image editing app.)
Not quite. This is kind of complimentary to the anamorfake techniques in that it squeezes the image, which the lens mods don't do, but doesn't produce oval bokeh.
I got one on Ali Express for ~30 USD and I think it's pretty much the same as the more expensive ones elsewhere.
Good point, I should have said vertical oval bokeh. Desqueezing will produce slightly horizontal oval bokeh, but the tiny bokeh balls that smartphones are capable of being ~25% wider (not 33% as advertised) is going to make fuckall difference. For example https://www.youtube.com/watch?v=MV-GGmTiyyc