I recommend Blue Wallet and Green Wallet for beginners. Blue Wallet is much simpler than Green wallet, so I recommend that one. 

A few days ago I gave my first Bitcoin Workshop for Beginners to 11 people and we used Blue Wallet. I sent each person bitcoin on-chain but Blue Wallet crashed each time using the batch function. Then I tried to send each person individually, but it gave me an error about a fee rste I never saw before.. After that I sent it with Relai without issues.

I very much like Sparrow Wallet, but that is on a desktop, which is where most people do everything with and is less secure than a mobile wallet I guess.

Any suggestions for sending bitcoin to participants?