iOS is known as a walled garden, but developers have worked out a bunch of ways around that garden to automate tasks between apps. Most of these tricks are a bit complicated, but MacStories has a starter guide that shows off how to use Launch Center Pro to automate all kinds of things.
iOS has three main apps that make different types of automation possible, Launch Center Pro, Drafts and Editorial. Launch Center Pro is essentially a speed dial for common tasks on your iOS device. Once you set it up, you can instantly launch specific functions in any app from Launch Center Pro. For example, instead of opening up OmniFocus and tapping through to create a new to-do, you can use Launch Center Pro to create that new item instantly. You can even change the brightness and read text out loud.
MacStories' guide teaches you pretty much everything there is to know about automation. It's a massive guide, but it's a great place to start if you're interested in iOS automation.