Live Web Casts with iPhone 7

Hello,

My church is a small church. However we are touching over 10,000 people weekly on Facebook.

We currently use a single iPhone and pan from the Pastor to the Screen that has a verse or image that is pertinent etc. When the band is playing it is essentially focused.

My question is is there a device or software that can have each image brought to a hub and have a producer (for lack of a better word) select the image that best suits the sermon being taught?

When I was in HS in the late 70’s we could connect three or four cameras into a Special Effects Generator (SEG) through large cables and we could fade or wipe from one Camera to the next.

Does anything like that exist that can be used from a mac book and using iPhones? We don’t have a lot of money so this would be a real cost savings. We also don’t have our own building so permanent installs are out.

Thank you in advance!!!