When I make a call and get put on hold, I would like to be able to put that call on hold from my end and then have my phone ring back to me (custom ring/screen notification) when a live person comes on the line. This service would notify the party on the other end that "Your caller will be right back -please stay on the line" so they don't hang up. Google Pixel apparently has a similar feature https://support.google.com/pixelphone/answer/10071878?hl=en .