[delluminatus]

Actually, Amazon already did -- one of the sample Lambda functions you can use is just that. It runs on a scheduled timer, and if I remember correctly, will alert using AWS Simple Notification Service, which can be configured to send alerts to your devices or emails.

[vacri]

Unfortunately, unless it's changed recently, SNS can only send SMSes to US numbers :/

[dorfsmay]

https://www.twilio.com/sms