Beware! What starts as a simple quest to "see messages and devices on the network with a computer or app" can become a deep dive into connecting your boat and everything in it in more ways than you imagine. It's a pursuit parallel to sailing that many of us enjoy.
If you eventually want to monitor batteries and maybe tanks the Victron Cerbo GX is almost a bargain. Cost is not much more than a Raspi with a hat, case, fan and connectors and everything is in one tidy Victron blue package.
Cerbo (like the Pi) can be viewed via wifi on phone, iPad, computer, etc. If your boat has starlink or a cellphone hotspot it can be viewed over the internet from any location.The Victron Venus software has a SignalK option built in (Node Red too).
The Cerbo can be integrated into Home Assistant which is solid open source software, lots of tutorials and threads with information about HA, just mind the dates of things you read - info from a year or two ago probably has changed.
This guy on YouTube does "smart" van stuff, lots of good information there. Rob at smartboatinnovations.com has similar content but specific to boat navigation, monitoring and life aboard convenience.