We have successfully launched HMRC Tax Calculator using HMRC API (Beta) version on Testflight for beta testing, our clients are testing all the functionlaity and enpoints, if you need to look at this version, please email us then we can send you a link to download.
This version is also available in android, so let me know if you need the apk for testing purpose.
Once the beta testing is completed we are going to publish in app store and playstore, so it’s avaliable to everyone.
HMRC has only release Marriage status endpoint (stable version), which means in production you would see only this enpoint working.
But we would release test data endpoint in first release, as we can get familiar with the endpoints, later we can can launch another release which refers to HMRC production data (once HMRC is ready with stable version).