Hey, thanks for the kind words! I'm not sure why it's not working in the itch.io app, I'll be working on a fix, it will hopefully be ready today.
As for organizing tabs, it opens alternatively on the right, then on the left. You also can click on an already opened tab to turn it red, which will lock it, and all other tabs will now be opened on the other side.
edit: It might be a bug on itch.io's side, I posted a bug report, I'll keep you updated.
edit2: It looks like it's working now!