Lesson 1: Introduction to Apps


Students explore and investigate what makes an app an app. They begin by looking at and discussing five different apps. Following this, students watch a video explaining the basics of how computers work. Finally students return to the apps and consider the various inputs and outputs.


This lesson is an introduction to a unit that introduces programming through the broader context of designing apps that help people. This lesson is designed to build excitement about the skills that students will develop throughout the unit and get them thinking early about the ways programming can help others. This lesson also establishes shared vocabulary for talking about apps in a generic sense, for example its inputs, outputs, and overall user interface.


Lesson Modifications

Warm Up (5 mins)

Activity (30 mins)

Wrap Up (10 mins)

View on Code Studio


Students will be able to:

  • Identify the inputs of an app
  • Identify the outputs of an app
  • Identify the purpose of an app


  • Preview the How Computers Work Video
  • Explore the apps used in this lesson


Heads Up! Please make a copy of any documents you plan to share with students.

For the Teachers

For the Students

Teaching Guide

Lesson Modifications

Attention, teachers! If you are teaching virtually or in a socially-distanced classroom, please read the full lesson plan below, then click here to access the modifications.

Warm Up (5 mins)

Discussion Goal

Apps are designed to solve a problem by providing a service

  • Entertainment: images, movies, tv shows, etc.
  • Social: social media, chatting
  • Commerce: marketplaces
  • Finding Information: search engines, maps

Apps have screens or User Interfaces to display and collect information to and from users

  • These things collect information: Buttons, sliders, text boxes, etc.
  • This is the type of information that can be displayed: Sounds, images, video, text

Preview the Unit


Now that we've learned how to represent information digitally and how the Internet works, it's time to think about creating digital content for others to interact with.

Prompt: What are apps? How do we interact with them? What kinds of things do apps do?

Activity (30 mins)

App Exploration


Today we are going to be looking at some sample apps to explore their purpose and function.

Group: Organize students in groups of two. Students should navigate to the App Exploration starting on level 2.

Levels 2-6: There are five different sample apps. Depending on time, students can explore 3-5 different apps.

Discussion Goal

App #1: Water Conservation Tips

  • The user clicks through the different screens and makes choices about the correct ways to conserve water. When the user makes choices, images or sounds are played to indicate if a choice is the right one.
  • The purpose of the app is to teach people about ways to conserve water.
  • The target audience is young people who are interested in the topic

App #2: Bird Quiz

  • The user answers trivia questions about birds. If the answer is correct, they go to the next question. If wrong, they are taken to a losing screen, and then start the quiz again. If three questions are answered correctly the user is taken to the winning screen.
  • The purpose of the app is to teach users different facts about birds
  • The target audience is anyone interested in birds

App #3: Hamilton Township

  • The user clicks through a few different screens to learn about township efforts to beautify the town
  • The purpose of the app is to educate users on steps the town is taking to improve the town
  • The target audience is people who live in Hamilton Township

App #4: Four Square Instructions

  • The user navigates through different screens that explain how to play four square. On one screen, the user is quizzed on how many people are needed to play four square.
  • The purpose of the app is to instruct the user on the rules of four square.
  • The target audience is people who would like to play four square.

App #5: Monarch Butterflies

  • The user clicks on different screens and pictures of monarch butterflies to explore the life stages of the butterfly
  • The purpose of the app is to educate users on the life cycle of the monarch butterfly
  • The target audience is young people, most likely children or teenagers who are interested in life science and butterflies

Prompt: With a partner, discuss the following and note down in your journal:

  • How does the user interact with the app?
  • What is the overall purpose of this app?
  • Who is the target audience?

Share Out: As a class, discuss student answers to the discussion questions.


In developing apps, which are a kind of computing innovation, it's important to understand both their purpose and function. The purpose helps the developer focus on creating an app with specific goals in mind.

Now let's dig in to how the user interacts with the apps.

Input & Output

Display: How Computers Work How Computers Work - What Makes a Computer, a Computer - Video


The video explained Input, Storage, Processing, and Output. Today we are going to focus on input and output. An app on a phone gets input in many different ways from a user or from another program and displays (or in the case of sound: plays) output. The output of a program is usually based on inputs or the initial way the program was set up. For example, you could program an app to play a song as soon as it runs.

App Investigation

Teaching Tip

After students are finished writing in their journals, discuss as a class or collect the journals to review student answers.

  • An input could be a user clicking a button or tapping the screen
  • An output could be an image displayed or a sound played

Levels 8-12: With your partner, take another look at the sample apps you explored before by navigating to the App Investigations starting at level 7. Consider what the inputs and outputs are for the apps. Note these down in your journal.

Wrap Up (10 mins)


Apps solve a problem for a target audience. Apps take in input from users and output information in various ways. Users interact with apps through the user interface.

Discussion Goal

After students have shared with a partner, bring the class back together and discuss a few examples.

Prompt: Think of your favorite app. Discuss with a partner what the user interface looks like and the inputs and outputs.

Journal Add to your journal the following terms along with your own definitions:

  • User Interface
  • Input
  • Output

Assessment: Check For Understanding

Check For Understanding Question(s) and solutions can be found in each lesson on Code Studio. These questions can be used for an exit ticket.

Question: Match term with the example.

Standards Alignment

View full course alignment


CRD-2 - Developers create and innovate using an iterative design process
CRD-2.A - Describe the purpose of a computing innovation.
  • CRD-2.A.2 - An understanding of the purpose of a computing innovation provides developers with an improved ability to develop that computing innovation.
CRD-2.C - Identify input(s) to a program.
  • CRD-2.C.1 - Program input is data sent to a computer for processing by a program. Input can come in a variety of forms, such as tactile, audio, visual, or text.
  • CRD-2.C.4 - Inputs usually affect the output produced by a program.
  • CRD-2.C.6 - Input can come from a user or other programs.
CRD-2.D - Identify output(s) produced by a program.
  • CRD-2.D.1 - Program output is any data sent from a program to a device. Program output can come in a variety of forms, such as tactile, audio, visual, or text.
  • CRD-2.D.2 - Program output is usually based on a program’s input or prior state (e.g., internal values).