Navigating to Settings > General > VPN & Device Management to "Trust" the installation. The Dark Side: Risks and Legal Consequences

Finding a "clean" source is the hardest part (and the most dangerous).

On iOS, such apps are never found on the official App Store due to strict safety policies. "Exclusive" IPA versions are usually distributed through third-party platforms or Telegram channels.

What is SMS/OTP Bombing and how to prevent it | by Vaibhav Jayant

If you are looking for legitimate automation tools or open-source research projects for iOS, they are generally hosted on developer platforms: GitLab/GitHub : You can find various SMS Bomber projects on GitLab

If you are interested in SMS or notification stress testing for legitimate purposes (e.g., testing your own server’s rate limiting or your phone’s DoS resilience), there are legal, open-source methods that do not require shady IPAs: