Yes, but most of these tools provide you with a check from a single / datacenter location and mostly focused on uptime / reachability, while geoblock.net does that from home users and multiple countries.
FastNetMon is a life saver. First installed it when there was no paid / advanced version just to blackhole hosts under attack. Then negotiated with our upstream provider to have BGP Flowspec support e.g. block specific types of traffic.
Back then, UDP Amplification attacks were scariest of them all and FastNetMon was able to send Flowspec announcements to our upstream to block, for instance, traffic to UDP/53 port, which kept the host alive most of the times.
Turns out there are a lot of businesses that constantly get banned and they need a reliable source of notifications about that