The WordPress App for smartphones and tablets has been around for years and is getting better and better!
How to get the WordPress App running
You will need Jetpack installed on your site.
Jetpack will need to be connected to WordPress.com.
You will need a login to your site that uses an email connected to a WordPress.com profile.
Then you just need the app installed and login with the same email as on your WordPress.com account.
You will be able to post to any WordPress site that is connected via Jetpack and your email!
New and Improved iOS Sharing Extensions