Trialpay https://www.trialpay.com/
Ironsource http://www.ironsrc.com/
Typically you reward in virtual currency, but you can reimburse them in cash if you want to go through all the work of a cash-out policy with real money
Peanut Labs (Surveys) http://web.peanutlabs.com/monetization/ Offer Toro https://www.offertoro.com
Trialpay https://www.trialpay.com/
Ironsource http://www.ironsrc.com/
Typically you reward in virtual currency, but you can reimburse them in cash if you want to go through all the work of a cash-out policy with real money