By default your android phone will automatically update apps when you're connected to the WiFi network, for some people (like me) this is a bad idea.
Because newer apps is not always the best one, usually the old one is better, so i prefer update apps manually.
To disable auto update apps on android is simple, open google play store on your phone, and then choose "Settings" > "Auto-update apps" > "Do not auto-update apps".
That's it, very simple, now your phone won't automatically update apps, and you still can update apps manually.
~ cheers ~