I've just wrote about Cake DeFi here.
Now I must write about a temporary benefit for new subscriptions until 10th february.

Using a referral link like this, making a deposit of at least 50$, you will receive the usual 30$ bonus AND a plus of 8 DFi, for a total of around 48$ free.
Just note that all bonuses in Cake DeFi are freezed for six months, but can be used in the platform for staking, mining and lending products, while your initial deposit is free to withdraw, but my advice is to keep your money there for a while and try the services of this company.
By the way, if you're looking for referrals, take a look under:
Trading Platforms:
Binance
KuCoin
Bittrex
Coinbase
Bybit
DeFi platform:
Cake DeFi earn 30$ in DeFi as you deposit 50$. Bonus of 8 DFi until 10th February.
Games:
RollerCoin earn BTC, BNB, Doge, ETH... playng easy games register with this link to earn1000 Satoshi
Coin-farm a very silly game, didn't test it deeply but I want to.
Cryptopoly a brand new city building game.
Other:
CryptoTab a browser that let you mine small amount of BTC, a good referral program, but needs 2/3 days for payouts.