IOST Community has recently launched testnet of IOST Coin which become huge papular across their community. IOST Coin started a referral program to reward their community. You can earn 100 IOST coin by referring to a user. IOST Coin has to been listed on the following top 5 exchanges:
1- Upbit
2- Binance
3- Bitfiniex
4- Huobi
5- Okex
You can get 20 IOST coins by signing up using below link:
https://hub.iost.io/register?inviteCode=B1f-IwDVX