Fido

You can have your iPhone's LED light flash whenever a notification comes in as an extra way of alerting you to new activity: from Settings, choose General then Accessibility and then toggle LED Flash for Alerts to the on position.

On Android Marshmallow, go to Settings, Security and Screen pinning - when activated, you can 'pin' apps from the multitasking screen, so the app can't be left without a PIN. Handy for lending your device to others

 Put your phone in airplane mode and it will use much less battery life and thus charge more quickly.

Siri, Google Now and Cortana let you turn off Wi-Fi with your voice. Just launch your app of choice and say "turn off Wi-Fi" to achieve the desired result. It works with Bluetooth as well).

Set up a recipe on IFTTT and you can get alerts sent straight to your phone if the weather gets bad