Monitoring with output to the phone?

Question

Monitoring

Good afternoon. We need some kind of simple monitoring system, with real-time output on the phone. Banal online \ not online. Checking is better with pings .... probably)
If it will be possible to write also to the cart, about those who have not been online for a long time - it will be good

. Is there anything other than zabbix? maybe sooner?

Answer 1

Optional Monitoring Simple and free

Answer 2

https://uptimerobot.com
50 free monitoring