The application code has not been updated to the latest Flutter 3.0 version, which may cause significant issues with outdated legacy code if you purchased it in 2023 or later. Consequently, you might encounter difficulties generating a build for the app.

Despite this drawback, the core code itself is of good quality and well-structured. For those familiar with Flutter, it presents an opportunity to extract the code and redevelop their own app using this as a foundation.

However, for individuals unfamiliar with Flutter, I would recommend exploring alternative options. This particular app may pose considerable challenges for those without expertise in the Flutter framework.

In conclusion, it's regrettable that the developers have not maintained this app up to date. It possesses great potential and usefulness, and one can only hope that they eventually update it to align with the latest Flutter version.