On a German website I found a big promising list of flicker free LED bulbs available at least in Germany:
FfT means "flicker free techniqually", which should be our first choice.
FfH means "flicker free for humans" which is worse.
What they list is the so called "Compact flicker degree" (CFD). It looks complicated, and I have no idea what it really means. I didn't find an English Wikipedia entry for this.
If someone finds a link which explains it in English, please share. Here he explains it in German: http://www.derlichtpeter.de/der-kompaktflimmergrad-cfd/
It seems there are a lot of ways to measure "flicker" degree. This CFD method is some complex formula as opposed to other "easy" ways like (MaxLight-MinLight)/MaxLight.
I think the listed bulbs may operate in some other European countries, too. Not sure about other world regions. I think there are different technical standards (50 Hz vs 60 Hz and others...).
But maybe some of you live in Europe so it may help you.
Edit: He recently invented his measurement method himself, that's probably why it's not known yet internationally.