Be advised Blink app does not have a multi user account feature. Only 1 user name and 1 password is all you get. That 1 name and 1 password can be used on multiple mobile devices however. The biggest problem is everybody has the same power to change anything.
Another problem is more than one person logged in at same time. The mobile devices will compete with each other trying to do more than one thing at the same time. AKA you can’t watch the same video clip, multiple videos, or change settings at the same time. This might be what you were referring to…knocks the first phone offline. Remember, the mobile app is 1 person account and 1 mobile device at a time.
Anybody logged in with your account can change settings, delete video clips, etc. They can also change password and lock everybody else out. With that in mind, decide if you really want to share your account name and password with additional people.