There really is no one way to introduce devices or tech tools to kiddos. I have used a few, depending on my purpose and the amount of time I've had available. I have found each of them to be highly successful.
1) Interactive Modeling - I often use this Responsive Classroom practice to teach kiddos how to use use devices and/or tools. When I want them to understand the one way to turn devices on or off, adjust the screen during a mini-lesson, or how to include a hashtag or mention someone in a tweet I use Interactive Modeling. I show them how to do it, they share their observations, a kiddo demonstrates and they share their observations, and then they all get the opportunity to try it out.
2) Guided Discovery - Another Responsive Classroom practice, I use this when I want kiddos to construct their knowledge through inquiry, discovery, and sharing. I've used when introducing kiddos to apps like Talking Tom, Doodle Buddy, or Weebly. During Guided Discovery I introduce the kiddos to the app and then give them time to explore it. During this exploration phase they are seeing what the app is capable of doing and even problem solving. After exploring, they share their discoveries with their classmates, creating a collective knowledge of how to use the app.
3) Sometimes I just introduce the app to one student, making them the expert in it. Once they've figured out all of the app's little details then I unleash them on them rest of the class, having them teach how to use it. Or even stating, 'If you'd like to learn how to use Fuzzwhich be sure to see Dylan. He can show you how it works.' Sometimes, all it takes is one kiddo!.
4) Be the Expert - Sometimes I will even give them a choice of an app to explore. I may have 2-6 apps listed for them to choose from. I'll give them a brief description of each app. And then I have them sign up to explore one of the apps. They sometimes will do this alone or with a partner. Once done exploring, they share out in the group, very similarly to when we do Guided Discovery. They then become the experts for this app and are the ones to go to for a trouble shooting session. I sometimes will the do the same for more complex tools like Weebly; I'll have a few kiddos become experts in certain areas like inserting HTML, altering text, etc.
Depending on what the learning goal is, the amount of time available, or how complex the tool or concept is will impact other things. For example, if the tool I am introducing, like Weebly, requires an extensive Guided Discovery time then I may have them initially do something more simple with it. Although Weebly is very user and student friendly, the possibilities for personalization make this necessary! Other times, if what the concept they are working with is complex, I will have them use an app they are already familiar with or requires less trouble shooting. Keeping these things in mind can make the integration of tech more sucessful!