How can I remove a fake app from my iPhone?

This is a Japanese website which can hack into your computer and apparently store all of your passwords to all of your apps on a local driver wherever they are. Then, when you find it, say in Google passwords, which you can change as a listed server/website, it magically changes to look like the regular app website, while it still hosts your passwords within their database. Any information on removing it/them completely from device before calling apple support (already had a phone bricked and disabled from probably the same company) would be greatly appreciated.

[Re-Titled by Moderator]