Hacked!

If you feel an unauthorized person/app is remotely using, controlling or monitoring your device, then that is possible only if you have done one or more of the following Don'ts...

1. Don't hand over an iPhone to kids or to a stranger without Enabling Guided Access
2. Don't share Apple IDs
3. Don't Jailbreak
4. Don't share sensitive information pertaining to your device
5. Don't give in to Phishing
6. Don't plug in your device in Airports and Public places through third-party cables and trust the device. Beware of Juice Jacking. (Especially in India)
7. Don't leave your iPhone unlocked and unattended in public places like offices, schools, malls, etc.

If one of the above is true then quickly change the Apple ID Password and Return iPhone settings to their defaults.

All these can be accessed through many channels need not be an iPhone.

Instagram is not an Apple Product. Contact the app developer here --> App Support  or Instagram Help Center

Facebook is not an Apple product. Contact the app developer here --> App Support or Facebook Help Center | Facebook

Amazon Alexa is not an Apple product. Contact the app developer here --> App Support or Alexa Devices Help - Amazon Customer Service