why does my iPhone say that it is in Russia, when I am in Hamburg? I have used the app phone search

The only app I know that can locate your phone is "Find My iPhone" Free Find My iPhone: Frequently Asked Questions

If your App is called "Handy Ortung..." or similar, your app might be for entertainment purposes only, check the App Store again and have a look at the description or reviews.

Did you try to open "Maps" on your phone and hit the little arrow in the left corner to show your location?

Did you try the same thing being on Wi-Fi?

Had a similar problem, The iPhone said I was in Germany when I was in the UK!! Also changed local time etc. 30mins later I was back in the UK. Wiped the phone just in case of software problems but still had the intermittent fault. Made appointment with Genius bar and they replaced my phone, so far so good. Looks like a hardware fault.

Hope this helps.

Try to set it up as new device, without using the latest backup afterwards. Don't put any other apps than the default apps on it and try again. How to back up your data and set up as a new device

If the phone works after that, add the 3rd party apps back and check again.