NookCRM is built on top of CiviCRM, an open source and flexible CRM tool popular with charities and social impact organisations. Like CiviCRM Nook is also open source.
This means that someone experienced with configuring CiviCRM should be able to configure your Nook setup or customise many aspects of it for you.. Or a CiviCRM developer should be able to make direct code changes and build new custom features.
You can find a list of CiviCRM “partner” developers through the official CiviCRM partner directory (being developers who also support the core CiviCRM development), you can find a developer via a simple online search, or post a job on the CoTech community forum (CoTech is a network of ethical tech, digital and creative co-operatives).
Already work with a developer? CiviCRM itself is built using PHP, a common coding language, so a developer comfortable with PHP coding language should be able to learn CiviCRM.