Useless. It never notifies me when I have a message. I have made sure all the notifications were on and that my phone permissions weren't preventing any thing. Turns out this is a common issue and steam has no fix (according to multiple reddit forums I found) so what's the point of the app? I got this so friends could message me when I'm away from my computer so we could coordinate game time. Now ur telling me I can only get notifications if I'm at my computer? Ridiculous.