App is pending Play Store and App Store approval. In the meantime Android apk can be accessed here in downloads.
But you need this extra step to allow Android to forward notifications:
On Android 13/14, apps installed via APK (“sideloaded”) often have Restricted settings enabled. This disables “Notification access” (and Accessibility) toggles, so the page/toggle appears greyed out.
Fix on the phone
Go to Settings → Apps → ZSWatch
Open the menu (usually ⋮ top-right) and tap Allow restricted settings
Then go to Settings → Security & privacy → More privacy settings / Special app access → Notification access
Enable ZSWatch
If you don’t see “Allow restricted settings”, it can be under: Settings → Apps → ZSWatch → Restricted settings.