A tool for back to back meetings

Hi

I am collecting feedback to validate my idea on whether I should build the product or not

A Mac/windows app that pop’s up on your screen minutes before meeting starts and lets you send a message (e.g. running late by 5 mins) in next call directly without you joining it, while you are still in your current call.

It can also show participants who have joined in real time so you can decide to extend your current call if others are also late.

Have some more ideas as well but this is the key feature. Would you use such an app