Some Ads blockers, Proxy servers will install root certificates on your iPhone or iPad in order to block ads, capture packet, inspect network traffic. However they pose a potential privacy and security risk. If you worry about exposing your financial transactions and private communications, you can toggle it off or remove it from your iOS device.
Go to Settings > General > Profile. Tap on the certificate you want to delete. Tap Remove Profile. Enter your passcode if prompted. Tap Remove to confirm.