Mochi NetProbe
Tap scan and NetProbe finds every device sharing your Wi-Fi — not as a list of numbers, but by name: the printer, the thermostat, the TV, the one you don't recognise. For anything with a web interface, it will also tell you what software is running behind it.
Not 192.168.0.94 but Brother MFC-7860DW — with its manufacturer, model, and the fact that it accepts print jobs three different ways. NetProbe asks the network five different ways at once, because no single method finds everything.
Anything that wasn't there last time you scanned is marked new. Name a device once — "Rachel's iPad", "the garage camera" — and the name sticks, so next time you're only looking at what you haven't already accounted for.
For devices with a web interface, NetProbe reads the response the way a developer would: the web server and its version, the language and framework behind it, the TLS certificate and when it expires. Routers, NAS boxes and cameras all give this up readily.
Every conclusion carries the evidence it came from and how strongly it's held — declared when the server named itself, likely when it's inferred from a cookie or a header, possible when it's a hint in the page. A guess is never dressed up as a fact.
Ping, traceroute, port scan, DNS lookup, WHOIS, Wake-on-LAN, a Bonjour browser, and a plain view of your interfaces and routes. Custom address ranges when you need to look somewhere other than your own subnet.
The scan runs on the device and the results stay there. No account, no sign-up, no analytics — we don't know how many devices you have or that you opened the app. Two features reach the internet, WHOIS and the public-IP check, and both only when you tap them.
NetProbe reads; it doesn't reach in. It asks each device what it will freely say about itself and reports the answer. It doesn't try passwords, doesn't exploit anything, and can't block a device from the network — no iOS app can, whatever the App Store description says. It's a tool for understanding a network you're responsible for.
Answers to the common questions are on the support page, and what the app does with your data is in the privacy policy.