Hi there
Can I ask, why does this have to be a mobile app? For the simplicity sake, and since it is easier to use, a web app would be a much suitable solution for this.
Now, do you have anything more than an idea for this project? For example, what steps should exist in this tutorial of yours? How would a developer get over them? Maybe layout for them?
Anyways, if you like the web app idea, feel free to hit me up so we can talk more about this. I am very responsive. All the best