I have worked with many non-governmental organizations. Many of them are local ones in Seoul, while some are bigger ones with many branches around the world. For this page, I want to introduce my small NGO friends. If you are interested in one of those NGOs, please let me know! Many NGOs are looking for partners to be with, and I would be more than happy to introduce you to these organizations :)
Saeil Academy: http://www.saeilacademy.org/
North Korea Reform Radio: http://www.nkreform.com/
PSCORE: http://pscore.org/xe/
NKDB: http://www.nkdb.org/2016/main.php
Justice for North Korea: http://www.justice4nk.org/en/
NAUH: http://www.nauh.or.kr/eng/main/main.php
Transitional Justice Working Group (TJWG): https://en.tjwg.org/
NK Global School: Website not available
Imjingang: Website not available
Mosarang: Website not available
.. and more
And some bigger organizations you might be interested:
International Christian Concern: https://www.persecution.org/
Human Rights Watch: https://www.hrw.org/
Amnesty International: https://www.amnesty.org/en/