Here is a guide on how to post an instructable via iOS.

Step 1: Download

Download the Instructables application via the App Store.

Step 2: Create

Create an account, or log in with Facebook.

Step 3: Open the Menu

Open the menu at the top right of your screen and click "New Instructable"

Step 4: Select

Select your category and language.

Step 5: Add

Add images and text as you see fit.

Step 6: Click

Click "Publish" at the top right of your screen. Also, add "Tags" or words that relate to your post. If you are doing a piece on making eggs your tags may include "Breakfast","Bacon", and "skillet". Once you are finished, click publish at the bottom of your screen and you are done!