Gravit Designer is a full-featured, free vector design app right at your fingertips.
You can use it online or download as a desktop app, there is a "Portable" package too:
Unfortunately settings are saved to 3 places (appdata, localappdata, etc), but hopefully this will change soon:
https://discuss.gravit.io/t/portable-ve ... files/6414
I've been watching the project from the very beginning, now they have been acquired by Corel:
We are back with the first big release of Gravit Designer after the acquisition by Corel