Blogger has an app for iPhone and it's better than the corresponding Android app, which has improved a lot in the past months. Both apps let you edit your existing posts and create new posts, add images to your posts, include labels and geolocate your posts.
They're pretty basic, but the iPhone app has a better interface, it's easier to use and pays attention to detail. For example, the iPhone app includes the URL of the blog next to the name when you switch to a different blog, so that it's easier to identify a blog. The Android app only shows the names. To publish a post in the iPhone app, you need to tap the "Publish" button, which is always displayed at the top of the screen. In the Android app you need to scroll to the bottom of the post to find the "publish" button.
"With the Blogger app, you can write a new blog post and publish it immediately or save it as a draft right from your iOS device. You can also open a blog post you've been working on from your computer and continue editing it while you're on-the-go. Your blog posts are automatically synced across devices, so you’ll always have access to the latest version," informs Google.