This app (formerly known as Greek WPA Finder) was
originally intended for use inside Greece
as it can recover
WPA/WPS Keys of specific router brands that are popular within Greece thus helping you test your network security.
Nowadays there is an ongoing effort to gradually
support more routers around the world.
If you are
you can still
try your luck
with this app but don't be frustrated if it doesn't fully work in your territory.
In case you manage to connect to a network othen than yours, you have to inform the owner so that he/she changes password.
Have a look at the GWPA Finder - FAQs here: https://thanosfisherman.github.io/posts/gwpa-faqs/