Pebble SDK

Pebble has a developer portal where you can get the latest SDK, browse the examples, and read the documentation.
https://developer.getpebble.com

Cloud Pebble provides a cloud IDE and emulator for developing Pebble code.
https://cloudpebble.net

Pebble has a built-in compass.
http://developer.getpebble.com/guides/pebble-apps/sensors/magnetometer/

More Pebble Examples:
https://github.com/pebble/pebble-sdk-examples