I find it easier to just use Slack for random notifications that I need, even if they have nothing to do with Slack itself. Just create a new Slack channel just for those notifications, use Slack API to send them out (simple curl is enough) and make sure all guilty parties subscribe to that channel. To make your phone go beeb boob boob add @channel to your notification message.
The good thing about Slack messages is that they already work on desktop, web browser, Android and iPhone. They're also free - you're not paying per message like you would with SMS.