In Android versions from Ice Cream Sandwich (4.x) to Lollipop (5.x), many phone manufacturers decided to select WiFi bands based on MCC+MNC from SIM card. For many countries, this information wasn't available thus these phones were not able to detect WiFi networks.
This Android app was meant to fix that issue that required the phone to be rooted.
What this application does is, after the system boots, modifies a system table with country information setting a country which will allow the phone to detect and work with WiFi networks.
First version supported phones with SuperSU apk only. This version, the second, supported any other apk to manage superuser permissions, like KingRoot, etc.
This was very usefull back at that time, maybe it will usefull for someone today. I personally tested it in over 100 phones from Samsung mostly and some HTC.
Compiled apk for this version can be found at https://www.yurguis.com/wifix/