We've added a way to easily create QR Codes for forms, sermons, events, groups, and service plans. As long as they are publicly accessible, you can generate the code by clicking on the QR code icon in the Share box when viewing a particular record.
QR Codes can also be easily generated for all public portal listing pages by going to the top of the respective listing within One Church and then using the dropdown next to the Add New button. For example, see below for how to get it for the public group listing page. For the giving portal, you can generate it under Contributions > Settings at the top of the page (using a similar dropdown).
Finally, there is also a standalone version of the generator under the cog menu in the header if you want to create QR codes with any text.