'Timeout3g' switches the data connection (edge,2g,3g,4g,H,…) automatically OFF when screen goes off (after a timeout) in order to save power. It brings the connexion back ON when screen goes on.
Time before disconnection can be changed in advanced settings.
Donate/Full version periodically re-connects so other apps can synchronize emails, messenger, whatsapp, etc.
If you are using a taskiller, then please add timeout3g to the safe list or it will not work: do not kill timeout3g.
Android 5.0 Lollipop is not compatible anymore, blame google here: http://tinyurl.com/o4hrexg
or if your phone has ROOT privilege get in touch for the ROOT version.
Keywords: power, "timeout 3g", "apn switch", "data switch", "t3g", "3g switch", juice, snapdragon, green, battery, 4g, lte, switch.