To be honest I don't have enough information to make an assessment. There are some issues which I think would need to be addressed before I would be terribly impressed.
1) What size zippers will it fit? No information on that that I can see. If it fits a #3 that's all it will be good for. That one example where they clip the slider off is a pre-made neck/skirt zipper and is probably a #3. Since lots of gear uses a #5 is that size available?
2) Zippers need properly fitting sliders to work consistently and reliably. Each manufacturer may have its own configuration for the slider. Some have a flat back panel, some have an lip channel on the back panel. Different teeth heights are made. This has nothing to do with the size of the zipper which measures the width of the teeth when closed. It is reasonably possible to close up a zipper with an ill-fitting slider but to get it to work consistently and reliably would be the trick. So while you might be able to get the zipper closed you might not have a slider you can use for a permanent replacement. Fat lot of good a closed zipper with no slider is.
3) In my experience, which is admittedly narrow, the slider is the most robust part of the zipper. I've had pull tabs break off a slider. I've had teeth get damaged. But I can't think of a single time where the slider has failed in and of itself. Seems like a solution to a problem that really doesn't exist.
There are similar items that I have seen on occasion but I've never really paid much attention to them for the reasons given above. Neat gadget. Annoying sound track imo, and extreme lack of information in the video. I'm not interested enough to look up the website and check prices and available sizes.
There's my opinion. FWIW