I like to use my smartphone with all functions always activated, but this is naturally a thing which contributes negatively to battery life. I tried to switch off, for example, the Bluetooth when I'm not using it, but then I get back to my car and only when I'm receiving a phone call I discover I'm not linked with the car because I dismembered to reactivate the Bluetooth function... So, no... I cannot use a device in this way. Recently I discover a little (but powerful) application which helps me doing this automatically: NFC Task Launcher. Yes, the name means you should use it with NFC tags, but developers also add other interesting features even without NFC: wifi connect/disconnect, bluetooth connect/disconnect, gps position, ... To show you how my smartphone usage has changed, I just describe some tasks I added to this application.

1. Event: Connection to Home WiFi. Actions: disable GPS, disable 3G data, disable bluetooth
2. Event: Disconnecting from Home Wifi. Actions: Enable GPS, Enable 3G Data, Enable bluetooth
3. Event: Connection to Car Bluetooth system (done automatically after wifi disconnection event) Actions: Disable WiFi, Switch to Driving Mode
4. Event: Disconnection from Bluetooth car system Action: Enable WiFi, Switch off Driving mode

And some other events when I'm at office, when will be night, when I'm in a specific GPS position (i.e. to the gym switch to vibrate mode). The application allow many other actions like send a message, start a phone call, make a chekin on facebook, start an application, set an alarm, ... You can do what you want, you just need imagination!! :) And then, of course, if you have NFC tags (actually are not too expensive) you can improve the usage of the application. For example a task "when is 22H set lock phone mode and add an alarm for 7AM" is not bad, but, if you are outside for a party the task is still fired. If you put, for example, an nfc sticker near your bed, you can say this task will be execute when you put the phone on the sticker (Near field communication)! :) With all this stuffs executed automatically, I don't need to take care about switch on and off functions but I can say that I don't need to charge my battery any day like before![gallery link="file" ids="853,854,855"]

youtube.com/watch?v=17ASsGo8kIk

UPDATE: After the post comment (you can read) about a different app to do something similar, I investigated a little bit and I found a better application (with more triggers and events available), in my opinion, easy to use and with a cool web interface: https://play.google.com/store/apps/details?id=com.arlosoft.macrodroid