esac

Google suggests a person who suggested the idea, who was the first to implement it at a decent scale?

I'm reading deep work by cal newport and I'm trying to implement his advice on allocating times of unreliability for deeper style of work.

The problem is that I need to be reachable at any time by 2 persons, no matter what.

My first idea was to use SMS only but alas, my ISP shares my number with the whole world and I get one SMS message every other day, another option was to use an external software IM (e.g. Signal) and ask those persons to join the platform to reach me. This would work wonders for me since I would add a flashy notification to my desktop and achieve my peace of mind but one of the two is not really internet/computer savvy and I can't be sure he'll be able to signup/install AND operate a telephone app in the time of need.

For now top bet would be to have a webpage they can navigate to and press a big red button to summon me on normal IMs, do you have better ideas?