Is the PhoneRescue app safe and certified by Apple?

Phonerescue is not an iOS app. It is software for your Windows or Mac OS computer to recover software from a mobile device. Apple has nothing at all to say about some other company’s products for Mac OS (just as Microsoft has nothing to say about the MS Windows version of PhoneRescue).

Note that with iOS on iPhone 6 and newer devices with Secure Enclave, it’s not going to recover anything if the device isn’t working or cannot be unlocked with your device’s screen lock passcode.

I don’t see this app in the App Store.

Did you find it there?

If not, I strongly recommend you do not use it.

Apple doesn't "certify" applications. They require apps that are sold in their online stores to follow certain rules. However, they don't certify them as good or necessary.

Data recovery software doesn't work very well on iOS devices.