They just need to reproduce your API behavior.

App cloning isn’t about copying UI — it’s about reconstructing your protocol, headers, token flows, and request sequencing. If your backend treats client-enforced limits or client-provided trust fields as authoritative, a cloned client can bypass them without touching your server code.

HTTPS, token signature validation, and certificate pinning help with transport and integrity. They do not prove the request came from your official app, nor that the action is fresh and policy-compliant.

The architectural shift is simple: treat the mobile client as hostile. Enforce business rules server-side. Bind sensitive actions to server-owned freshness. Detect behavioral and replay anomalies instead of trusting static identifiers.

Full breakdown:
https://medium.com/@vaibhav.shakya786/how-hackers-clone-your-app-and-bypass-your-entire-backend-ae087993c1e2