GWPA Finder app
WPA/WPS Recovery Utility for specific router brands
Nowadays there is an ongoing effort to gradually support more routers around the world.
If you are not located inside Greece 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/