You can send videos freely with other app users through messages. With non-app users you can send via MMS in which case your carrier’s charges will apply.
Open Messages Tab , all messages/conversations will appear below
Click on the existing message or create a new one, conversation screen will appear
Click on the attachment icon next to the Compose field. A pop-up will appear.
Open the folder and select the video(s) you would like to send
Click on the select button. Your image(s) has been attached
Click on the send icon next to the Compose field
You can send maximum 1 video in one message.