Sometimes collaboration should be more personal and more fun than simply connecting to the home office's collaboration platform to read messages and update your project status. Collaboration can mean brainstorming while actually sitting together, even on a mobile device. That's what Whiteboard Pro ($2.99 for the iPhone, $1.99 for Android devices) lets you do: Put a shared whiteboard on two mobile devices that are on the same Wi-Fi network or connected via Bluetooth. What you draw on one will appear on the screen of the other, enabling true real-time collaboration. You can even draw on top of photos you've taken or images you open in the app.