We have used this since over a year and that promo works, it was just 10 USD before now 20 USD.
The method for free 10% of 100USD is in Free Cryptocurrency Passive Income Ebook yet now its 10% from 200USD.
While downloading Celsis App from AppStore/Play when registering put code - 1264701e39
Then send 200USD worth of coins into the app and get 20 USD free of BTC in 30 days.
Referral codes MUST be entered upon account registration. The referred user’s initial $200 deposit must be held in their account for at least 30 days. Referral rewards are locked for 30 days.
I have used these guys since long of time with friends and never had issues but of course count risk before doing it.
They have own token called CEL on ETH too which lets you get some discounts.