No more awkward "you busy?" texts or calls at the wrong time.
"I want to text to see if Klaus wants to hang out today, but did he tell me his day off was Tuesday, or Wednesday?"
"I should call and ask Kinga when her brother's wedding is, but what if she's in a meeting right now?"
"Is Adebayo done at the gym?"
It's not another messaging app or complex scheduling tool, it's the simple availability signal your phone has always needed.