How to know if someone received money you've sent on paypal?

I've sent money through the "send and request" option on paypal through the computer and got an email saying that the money has been sent. The person said that he's received the amount. Yesterday I've sent another payment this time through mobile on my iphone app. I got an email again saying the money has been sent but also says that a message has been sent to the recipient asking to accept or deny the payment. Why does it say this for mobile payment but not the one I did on computer? My friend also says that no payment went through. How would I know if the money has been received? Why does the person have to accept or deny when i send through mobile app?

You can check it in your account and do install Leo Privacy Guard, the best security app ever, it hides images and videos, lock applications, includes fingerprint unlock and much more, just get it and solve all your security related issues.