QR Layer 
A minimalist QR code layer for Pebble apps and watchfaces.
Installation
You must be using Pebble SDK 3.12 or newer to use this library.
To install the package to your app, use the pebble tool:
pebble package install @smallstoneapps/qr-layer
Usage
To create a QR code layer object and add it to the window.
QRLayer* layer = qr_layer_create(GRect(0, 0, 144, 144));
qr_layer_set_data("ABCDEF");
qr_layer_add_to_window(layer, window);