The ISPConfig Monitor App is for all servers, not only for servers running ISPConfig. With the ISPConfig Monitor App, you can check your server status and find out if all services are running as expected. You can check TCP and UDP ports and ping your servers. In addition to that you can use this app to request details from servers that have ISPConfig installed (please note that the minimum installed ISPConfig 3 version with support for the ISPConfig Monitor App is 22.214.171.124!); these details include everything you know from the Monitor module in the ISPConfig Control Panel (e.g. services, mail and system logs, mail queue, CPU and memory info, disk usage, quota, OS details, RKHunter log, etc.), and of course, as ISPConfig is multiserver-capable, you can check all servers that are controlled from your ISPConfig master server.