We created Monique.io because we were tired of the "same old, same old" monitoring systems that didn't help much with a lot of daily tasks.
We launched Monique.io a few months ago and now bring improvements and a free plan (which we are committed to preserve; the plan does not include alarming functionality).
(Yes, call me a free rider, a jerk or whatever you want, but I do sometimes I end up becoming a paying user of some services after using them for free for a while.)
If you are a programmer, then probably the most honest description would be that it's a monitoring system for "custom metrics" - anything that a traditional monitoring system or an APM platform can't collect (because it requires application-level knowledge like the data model in your DB). The traditional monitoring systems are focused on system-level metrics (CPU, memory) or performance data, making things like monitoring SQL results or JSON really hard and unnatural. Monique.io makes such tasks much simpler and "natural".
Another view is that the common knowledge about what is "monitoring" cuts out a large portion of things that really should be monitored (SQL results, health checks, API responses). The reason is that we can't collect the metrics automatically. But the work should be done and the traditional products don't provide much help for the task.
(saying all that, we and others use Monique.io also for monitoring CPU/disks, creating "BI" dashboards or sending messages to Slack)