Hello Fellow Hackers.
Before you start busting out Kali Linux and start hacking into WiFi, did you check if someone already knows the password? There is an app called WiFi Map for both iOS and Android. It is pretty much a repository of WiFi credentials that are already known.
If you are wondering, wait how can this app be put in the app store? It is really used to share public wireless access points, that have passwords on it. However, many people post their personal passwords and share it with everyone. This app is pretty handy to have when you are on the go and need to find some WiFi.
The main site is: wifimap.io - You can download the app from there, or go to the app store and search for it.
This app has ads, however if you make an account with them the ads go away. I am not responsible for misuse of the app. Always make sure you are ALLOWED to use/pentest the network you are connecting to.