This year around July, Telecom Regulatory Agency of India (TRAI) developed its own anti-spam app called DND. Along with this, it established a new regulation also that required all smartphones in the country to have this particular app installed.
Apple refused to list this app on its App Store due to the fact that the app uses messaging logs for its functioning and puts questions on the privacy of the user.
The agency told that if Apple didn’t list its app on App Store within 6 months, it would ban iPhone from the networks belonging to all Indian carriers.
Considering India as the growing market for its mobile phones, Apple chose the safe way and now have listed the DND app on App Store.
You can download the app from here [link].Note: You need to be on iOS 12.1 or above.