Coding Challenge 2: Make an Encyclopedia App

Make an Encyclopedia App

Coding Challenge 2

This challenge will help you earn points in the Demo video section of the rubric.

In this challenge, you will...

  • Apply what you have learned about lists
  • Create an encyclopedia app

Key Terms

  • Encyclopedia - A book where you can look up information about a subject
  • Start Value - In App Inventor, this is information that you can pass from one screen to another.

Challenge: Make an Encyclopedia App

Create an app that helps the user learn about any topic you want. It could be famous people, popular movies, famous places, upcoming events, or anything else. Choose 3-6 examples of that topic and show their names on one screen. (For example, you could display a list of the names of women scientists.) When the user clicks on one of the names, your app should give them more information about it.

Welcome to your second coding challenge! This is a checkpoint for you to practice what you have learned so far. we recommend you solve this challenge in App Inventor, Thunkable, Java, or Swift, but you can solve it using the language you are using for your Technovation project

Below are the instructions highlight one way to solve it in App Inventor and in Thunkable.

Here is an example solution to help you get inspired:

Activity: Write Pseudocode

Before you start coding, try to write out some pseudocode to describe what you want your app to do. Here’s our example that we wrote out before creating our solution:

  • When the user opens the app, there will be a list of women inventors
  • When the user clicks on one of the women inventors in the list, the app takes them to a new screen
  • On the new screen, there is information about the inventor, her name and a description of her life.
  • When the users clicks “back,” the app goes back to the main list of women inventors

App Inventor Solution

Here’s a video tutorial made by Technovation alumni Jennifer. 


Written out Instructions

Thunkable Solution


Written out Instructions


Congratulations on completing your second code challenge!

  • Can you suggest any improvements that could be made to the encyclopedia app that would make it more fun and useful?
  • How would you change your app if you wanted to also show a picture of each woman inventor along with her description?


Additional Resources


If you cannot get your app to work correctly, you might have what is called a bug. A bug is just an error that you need to fix. Debugging is the process of finding and fixing that error. If  you want some debugging tips to help you find errors, check out Coding 14 - Debugging your App from Week 10.

Start Values in App Inventor

Each time you create a new screen in App Inventor, it is like starting a new app. Each screen runs independently and can’t access information that is on other screens. This means that the global variables in Screen 1 won’t be available in Screen 2. In order to pass information between screens you will need to use the open a new screen with start value block.