Video sending is tricky. I usually put stuff up on dropbox and send them the link. Too techy for most.
Anyhow, here's Verizon's app for that. https://itunes.apple.com/us/app/message/id621469412?mt=8
I have an s7 edge with nougat. I send a video via my text app which is Verizon Message+
The iphone user doesnt get the video. Instead he gets a thumbnail of the video and a message that says
"you have received a video. download message+ to view the video"
Why wont it just send the damn video?!!!