You can use Memfault's notification feature via email alerts and connect it to an external system, e.g. Slack, or BigPanda, that can help to monitor your fleet. Today there are only push notifications via email enabled. Cadence is on a nightly basis.
Many services can provide an incoming email that can be used to generate messages for the desired service. For example, Slack can provide an email that will send Slack messages to a chosen channel.