Almost all our apps use Core Data to store all kinds of data. This means that during development, we often want to have direct access to the SQLite data from our Core Data apps, in order to check things, detect errors, diagnose problems, discover data trends, and more.
As a Core Data developer you can use regular SQLite viewers to access this data. But it is never really fun or convenient to work with these apps. They don’t know anything about the underlying Core Data Model, so they can't visualize data relationships, they display entities and fields with strange prefixes, show field values in an unpractical way. Many SQLite apps have not been maintained for years, or are not even native macOS apps, so you often have to get used to all kinds of strange GUI stuff.
There are already a few dedicated Core Data viewers. But these are often functionally limited, or have features that are already in Xcode, such as Core Data code generation, or have not been maintained for years and are therefore plagued with bugs and outdated GUI concepts.
So we started to develop a tool ourselves. Over the last few years, our in-house Core Data viewer has grown so much that it would be a waste to keep it to ourselves. So we decided to transform the tool into an attractive app for other developers, and place it on the Mac App Store for a reasonable fee. The proceeds will allow us to maintain the app properly, provide support and add new useful features.