CodeBuilder

CodeBuilder is an easy to use app which creates QR-Codes, Aztec-Codes and Datamatrix. Just enter the text you want to encode, choose the type of your code and your code will be generated.

Generated Codes can be exported into a PDF document.

This app is free to use but occasionally ads are shown while codes are being generated.
To remove the ads you can do a one-time In-App-Purchase.