It appears to store data on their server, not in local files as Quiver does. It also looks like it may be (this could be mistaken, I haven't tried Inkdrop) an Electron app, in which case performance & memory usage is likely to be significantly worse than Quiver, which is not only native but very well optimized in my experience. On the plus side, it does have cross-platform support, which Quiver does not.

ETA: yup, grabbed the release and it is an Electron app - can't test without a beta invite, but for comparison on my machine it's about 3-4 seconds on launch before it gets to login screen, and uses 190mb of RAM at login screen. For comparison, Quiver is effectively instantaneous (a lot less than a second) to launch and uses 64mb of RAM displaying an empty document.

Quiver looks great. If only it ran on an OS I used.

Quiver uses cells, similar to Jupyter/IPython Notebook, and supports inline LaTeX, which is a very useful feature for when you need to display something outside the scope of Markdown (like an equation).