Use APKPure App
Get Locale Setting Widget old version APK for Android
Tap the widget, and you can open Android locale setting.
This is just a simple widget, and only allows you to open Android locale setting when you tap it.
Small size apk, and no permissions needed.
* The app does not have a home screen icon. Please add the widget to the home screen.
Downloading the source:
https://www.assembla.com/code/localesettingwidget/subversion/nodes