The ability with look@lan to connect into a client's network and quickly a list of everything reachable on the network was incredible. All the desktops, laptops, printers, etc. When I was doing WISP work, I could quickly see how many clients were online without logging into the far end (nowadays though, most WISPs will enable client isolation, but still good to see the APs and gateways).
Eventually look@lan was discontinued and then they released a tool called Fing, which also worked on mobile. But that turned into a subscription service. I did like the ability of fing to work from a phone, but the earlier Look@Lan was much more useful. I recently helped out a local non-profit who's network was all over the place, split up between two separate access points, each with their own subnet and they were having trouble reaching printers. Nmap helped out, but couldn't find a comparable tool to look@lan to help.
WatchYourLan looks like it will be a good substitute. I know it's primarily designed to run on one network and track changes to said network. And I will probably use it that way at home and a few other places (for the few customers I still maintain, if they permit, I will drop a small Pi/N100 box on their network for remote access and monitoring). But for dropping into a new location, I could see spinning this container up. I could do it in ephemeral mode or setup a data directory per "site" I visit.
There's a few tweaks I could see to make this more "mobile". such as adding a network or "site name" to the DB that you can config and filter on.
Another feature I'd be interested in would be fleshing out the port scanning a bit. Look@Lan and nmap scans for some common ports automatically. WatchYourLan has a port scanner, but you lose the information if you navigate away. At table for port scan results and an option to pre-scan specific ports. This would be good even for the permanent install - some might configure a set of default ports to scan on all the hosts in network, or they might customize for individual hosts.
But those are just my thoughts comparing it to tools I've used in the past. It's already a satisfying tool that's going to be added to my "toolbox". And since I also am a go dev, I might even be able to make some of those a reality.
https://www.ghacks.net/2008/08/11/network-monitoring-softwar...