Mobile stack

• Ads: Google AdMob (mobile) instead of AdSense (web).
• Analytics: Firebase Analytics (mobile) instead of web GA4.
• Billing: may differ between web checkout and app store billing.

Mandatory microphone permission

The app requires microphone permission to record attempts and score pronunciation. If permission is denied, speech scoring will not be available.

Azure-based audio processing

On both web and mobile, recorded audio is sent to backend services for pronunciation analysis with services such as Microsoft Azure Speech. In v1, attempt audio is treated as transient and not stored long-term unless explicitly disclosed later.