show it user status is on mobile
It would be great to see a status/presence of when a user is signed in only on their mobile. It helps other users to realize if the person they are contacting may have a delay in responding because they may not see the details on their mobile (perhaps they are driving).
Stacy Uden commented
This is also very relevant for globally distributed teams. It is very unfortunate to participate in a persistent chat, only to realize you caused someone's phone to be very noisy at 3am. That's a great way to encourage staff to hate the application (e.g., Teams).