Privacy settings on an iPhone can be set to ensure your blog says only what you want it to say.
Try not to inadvertently give information away about yourself - especially location/GPS information.
You may need to change some of the settings on your iPhone.
The following information assumes use of the Blogger app + iPhone
Go to 'Settings' on your iPhone (on your 'Home' screen)
Scroll down to 'Privacy'
Click on 'Privacy', and then 'Location Services'
If you've successfully uploaded the Blogger app to your iPhone you should see it listed here. Slide 'Location Services' to off