What are /r/hexcellslevels' favorite Products & Services?

From 3.5 billion Reddit comments

I don't know how this idea never occurred before, but here we go, finally, instead of having to look at Hexcells level v1 and a bunch of random characters, you can see full-fledged previews of levels; instead of fiddling with text selection you can copy even the whole level pack with just one click.

Note that this is not an actual browser extension but a userscript, so first you need to get a userscript manager like Tampermonkey. That's because maintaining full-fledged browser extensions is annoying and needs separate work for every different browser.