NextStats is a system monitoring app for Nextcloud instances.
It is designed with a focus on monitoring multiple instances with system status viewable at a glance, with more detailed statistics being just a click away. Though it works just as well if only monitoring a single instance.
NextStats has been tested to working with Nextcloud instances version 15 and up, with support for monitoring internally via IP address and externally using SSL (https) on qualified domains.
Servers using 2FA will be supported in an upcoming release.