Onboarding begins where a potential user, who has just downloaded your app, starts your app for the first time. You will have to convince that user and make sure that he instantly will notice the app's benefits. You want to convert your potential user into an engaged and active user, and this process starts with the first view that your app displays. To accomplish this, the first impression of your app should be interesting from a visual perspective and it should explain why the user should use this app. One of the ways of doing this is to create an introduction view with one or multiple slides. Remember that on a mobile device there is limited space, so you need to keep it short and simple. It should clearly explain the why and the what of the app. How things exactly work is something for later.