Hey cuteguy,
I found it when googling around for thai info, came across this site which reviews it
http://afarangabroad.com/find-thai-girlfriend/
I don't know if they are associated in some way but says all good thing about it so must be
You can signup for free, and it works only that there is limit to messaging i think you can send one message in 10 mins or so
I paid for it 25$ month, I advise to pay only if you have planned a trip, I look at it like if I spend 2K on tickets and hotels already it won't hurt another 25$.
Also it's not that guaranteed, you need to make sure you are not asking to sleep directly, just make it like you looking for potential GF or companion, many thai girls are actually conservative i have seen they don't want one night stand, make sure you look for open minded okay and yes there are sluts listed there
good luck if you are looking