If you want a ready-to-use app, download one of the many multi-account apps directly from the . This is the safest method as Apple has vetted these apps. Here are some of the top-rated alternatives:
If your device is jailbroken, you can install the IPA file permanently without worrying about 7-day expirations or revoked certificates. parallel space ipa
Apple designs iOS with strict security protocols. Every app runs in its own "sandbox," meaning it cannot see or interact with the data of another app. While this keeps iPhones incredibly secure, it eliminates native multi-account functionality. If you want a ready-to-use app, download one