Exercises: Programs and applications

Match each task with the type of application that performs it: (a) writing an assignment, (b) visiting web pages, (c) listening to music, (d) editing a photo. Types of application: 1. web browser; 2. word processor; 3. image editor; 4. music player. Give a real name of an application for each type.

Classify each item as system software or application software: Windows, the Chrome browser, Android, the phone calculator, GNU/Linux, a video game. Explain in one sentence the criterion you used to separate them.

True or false? Justify each answer: (a) a browser is an application; (b) the operating system is just another application, like a game; (c) without an operating system, applications cannot run; (d) a word processor is used for listening to music.

Which application would you use for each task? (a) writing a letter; (b) making a poster for a party; (c) editing and joining video clips; (d) reading email. Name real applications you know and explain why any application cannot be used for any task.

The figure shows the software classification tree with its two main branches, but one of the example cards is covered with a question mark, as shown in the diagram.

Which branch would you place the covered card in if it were a video editor? What if it were macOS? Explain the difference between the two branches and add a new card, with its example, to each branch.

The app store uses four verbs: search, install, update and uninstall. Explain in your own words what each one does and describe a situation where you have used (or would use) each verb.

Order these download sources for a program from safest to least safe and justify the order: the device's official app store, the manufacturer's official website, a link appearing in a pop-up advertisement.

Applications ask to be updated from time to time. Explain what an application update is and name two things that usually improve with it (bug fixes, new features, security), giving an example of each.

These are the steps to safely install an application, but they are out of order: (a) review the permissions it requests, (b) search for it in the official store, (c) check the developer's name and reviews from other users, (d) click "install" and check that it works. Put them in order and explain which risk each step avoids.

A racing game asks for permission to access your microphone, contacts and location. Analyse whether these permissions make sense for this type of game and decide what you would do: install it as it is, deny some permissions or look for another alternative. Justify your decision.

Your photo application has not been updated for two years "because it works fine". Explain two risks of not updating applications (unpatched security vulnerabilities, incompatibility with an updated operating system) and explain why automatic updates are a good habit.

Removing the icon from the home screen does not always uninstall the application. Explain the difference between deleting a shortcut and actually uninstalling, and describe step-by-step how you would uninstall an application to free up space on your phone or computer.

An unknown website offers a game for "free" that costs $\$400$ in the official store. Analyse the risks of downloading it from there (hidden malware, data theft) and what legal issues are involved in downloading pirated copies of paid software.

The figure shows the path an application takes on your phone, from when you discover it until you delete it, but one of the steps is covered, as shown in the diagram.

Which step is missing between "install" and "uninstall", and why should it be repeated regularly while you use the application? Describe the complete path and explain what can happen if you skip the covered step for years.

You have three applications that do the same thing (three different photo editors). Reason what advantages and disadvantages accumulating duplicate applications has, and what criterion you would use to keep just one: the space they take up, how much you actually use them, or the store ratings.

Many applications also have a "web version" that is used directly from the browser without installing anything (like webmail). Compare both options: two advantages of the installed application, two of the web version, and a situation in which you would choose each one.

Leo's phone has run out of space. His applications are: Game A taking $2\ \text{GB}$ that he hasn't opened for $8$ months, a video editor taking $1.5\ \text{GB}$ that he uses every week, Game B taking $900\ \text{MB}$ that he uses daily, a banking app taking $150\ \text{MB}$, and three games taking $300\ \text{MB}$ each that he hasn't touched since last school year. Design his clean-up plan: what he would uninstall first, what he would never touch, and how much space he would recover with each decision.

Marcos wants to install a racing game on his tablet and is hesitating between two options:

• Game A (paid): costs $\$3.50$ as a one-time payment, with all tracks unlocked and no ads.

• Game B (“free”): allows playing $2$ races per day; to play more without waiting $4$ hours, you must pay $\$0.80$ per fuel pass, or watch ads that consume mobile data.

1. a) If Marcos plays $4$ races daily for a month ($30$ days) and buys the necessary passes to avoid waiting, calculate how much money he will spend on Game B and compare it with the cost of Game A.
2. b) Explain why the Game B model is usually much more profitable for developers than selling the game outright, analyzing which software design mechanisms it uses to encourage spending.
3. c) Design two technical measures that Marcos should configure in his tablet's operating system to avoid spending money impulsively or by mistake.

You are going to set up a tablet for your grandmother, who has impaired vision, a slight tremor in her hands, and has never used touchscreens.

1. a) Design her home screen by selecting only three basic applications (communication, news, and hobbies). For the communication app, compare two real-market applications and justify which one you choose by analyzing which has a cleaner interface, fewer confusing menus, and a lower risk of accidental calls.
2. b) Design three specific settings that you must enable in the operating system (in accessibility, app store, and permissions) so that it is easy for her to read text, she does not get disoriented when tapping small buttons, and it is impossible for her to install or buy apps by mistake.

After a system update, your favorite application closes by itself when opened. Order a series of troubleshooting steps to fix it (update the app, restart the device, reinstall it after backing up your data, wait for the developer to fix it) and explain the relationship between system updates and application updates.

A messaging app widely used among your friends has been removed from the official store for failing to meet the operating system's security and privacy standards. Your group of friends is discussing what to do:

• Paula says: “Since we already have it installed, it doesn't matter; we'll keep using it over the next school years just like always.”

• Mario suggests: “For whoever doesn't have it, we can share the installer file (.apk) via Bluetooth or download it from an external website.”

1. a) Predict what compatibility issues and security vulnerabilities Paula's phone will suffer if she continues using it over the next two years.
2. b) Evaluate Mario's proposal by identifying what specific dangers he takes on by installing an app from outside the official channel.
3. c) Design a safe action plan for the group: what decision should be made regarding the removed app, and what technical requirements must the new tool you choose to replace it meet?

A classmate says: "I install applications from download websites because the store takes up too much space." Evaluate her decision: what security checks she is skipping, what could sneak onto her phone without her noticing, and what you would reply to convince her to change her habit.

Review the audit report for the mobile phone used to record experiments in the Technology lab:

1. Flashlight Plus: installed $3$ months ago; has active permissions to access the microphone, contacts, and location.

2. Audio Editor: downloaded from an external download website because it was paid on the official store; it has never received updates.

3. Puzzle Game: takes up $1.8\ \text{GB}$ of storage; the last time it was opened was $10$ months ago.

4. System and browser: have been displaying a "Critical security update pending" notice for $4$ weeks.

For each of the four situations:

1. a) Interpret the data and identify the technical, privacy, or performance risk it causes to the device.
2. b) Design the immediate corrective measure that the lab manager must apply and state the basic rule of "digital hygiene" that has been violated.

Your school wants to choose an application to send notices to families. Evaluate three options (a well-known messaging app, an app designed specifically for schools, using email) against the criteria of security, cost and ease of use for families, and recommend one, justifying your choice.