Create, share and save online sudokus
Traditionally sudokus are found in newspapers and puzzlebooks. These can be hard to save and share. That is what this little web-application does. You can try to solve a sudoku yourself. Just let the application generate one for you and try it out. You can also send a link to a friend. He then gets the exact same sudoku to solve, including the part you already solved. Finally you can also create an account to save your progress and continue your sudoku later.
Technology
This isn’t a WordPress theme at all. It is a so-called web-app built with different technologies. These apps are more suited for unique functionality opposed to standard use cases like webshops or brochure websites.
Angular is a front-end framework; a single JavaScript based web-page that processes data. This data can be present in the web-page itself, fetched from a database or both. You could e.g. have 2 people playing the same sudoku remotely.
This allows for a more modern approach to create a website. However there are also some major drawbacks: It takes far more effort to create and maintain; Everything has to be custom-made. It is harder to create SEO friendly pages, because the data changes all the time.
Firebase is a service from Google that allows you to deploy these kind of webapplications. It also has other services, like a database ( FireStore ) to store data, etc..
Summary
With technologies other than wordpress more interactive applications like this sudoku generator can be built. These are far more costly to create and maintain. But it could be exactly what you need and can be worth exploring.