Both iPhone and Android devices offer built-in options to set up call forwarding. Alternatively, you can dial carrier-specific codes if you don't want to navigate smartphone menus. Third-party ...

Android: Swipe down from the top of your screen -- to access the Quick Settings panel -- and then tap the Airplane mode icon.

but available for download on both Android and iPhone. You can use Google Hangouts to exchange messages in conversations with as many as 150 people at once, or conduct a video call with up to 10 ...