Checking your local WiFi network allows to discover all your devices and to make sure that no one penetrated it.
Free WiFi network scanner on your phone
Fing and Network Analyzer are free Wi-Fi app for Android and iOS (iPhone and iPad).
Remember to pause you VPN while using those apps.
Fing provides very useful information about wireless networks while being easy to use.
When you first open Fing, the app automatically scans the network you’re on to find all the different devices connected to it. Each device’s IP address, physical MAC address and host name are displayed and can be easily shared and saved.
Selecting a device displays information such as its provider, open ports (RDP, HTTP, POP3, etc.) and ping response, as well as the ability to wake it up if Wake On LAN is supported.
More info: https://www.fing.com
Network Analyzer Lite
Network Analyzer shows everything you could possibly want to know about the Wi-Fi and cellular network you are connected to.
The SSID, BSSID, provider, IP address and subnet mask are shown for the Wi-Fi network you’re connected to, and the IP address, mobile carrier name, country code and MMC/MNS are shown if you’re connected to a cellular network. Copying is supported so that you can save this information elsewhere.
Network Analyzer Lite also has a LAN tool that scans the Wi-Fi network to show what other devices are using the same network.
More info: https://techet.net
We like Network Analyzer better since it is more complete.