I was not aware you had a native app. The fact that it was running in a browser was the biggest concern for me: not only does that mean that the entire app is at the hands of the company making the browser, but there are several other drawbacks, like not getting quite the same hardware access, you waste a lot of space for the browser UI and so on. If Google decides to change something to the way they render fonts or change the way some script is loading, the app could easily be affected.

Is the native one actually native or just a web wrapper? It doesn't help that it completely froze for a full 2 minutes after I installed it on a fast computer.

To answer your other questions about what I didn't find it particularly impressive:

Live collaboration and the ability to save your projects in the cloud is great - kudos for that.

Aside from that though, what exactly can it do that other apps cannot?

• Allowing you to copy the CSS of an element? PS had that for years and it doesn't exactly replace apps like Avocode who do a lot more like allow you to make measurements easily or extract the SVG / PNG assets you need (that is a developer realises a designer missed an icon and gets it for himself straight from Avocode).
• Allowing you to create simple prototypes where you can go from one page to the next is hardly enough to replace other prototyping tools like InVision or even better Framer. (I'm going off what your instructions say here, if the prototyping tools can do more, I'm happy to revisit this).
• Is there anything else?

Because if not, I can understand this took a lot of effort to create but you have to see it from the user's point of view where you have a (what I thought was web only) app with an interface as clunky as Photoshop's (why not make it so that if you go more than one group deep you can't read the names of the layers anymore or bury everything under a text menu), and not a lot else to offer.