Use APKPure App
Get Switch Network Type 2G / 3G old version APK for Android
Faites vos achats sur Google Play sur le Web, et profitez-en instantanément sur votre téléphone ou votre tablette Android, sans synchronisation.
This app/shortcut opens directly the settings app of mobile network settings to switch between "2G" and "allow 3G" networks (e.g. to save battery). A direct switch is sadly not possible.
It places also a shortcut in the statusbar to reach the settings from everywhere.