Andreas Ramos | Professor of Digital Marketing | See andreas.com

Use AI to Build an App in Minutes

By Andreas Ramos, Professor at CSTU.edu, May 22, 2025, updated July 22, 2025

Adam Chen (General Manager at Analogix Semiconductor) gave a ten-minute talk at TEDxCSTU 2025 May 18th on how to use AI to make apps. Many thanks to Adam! I wrote up Adam’s guide as a PowerPoint for my students and assigned it as homework . All of them built apps.

Watch Adam's talk on YouTube. You can also see Adam's slides. See a list of 81 apps by Adam at PromptBox.cn.

You can build an app for your phone (Android or iPhone) in less than seven minutes. My first app took seven minutes because I had to figure out how to do this. I built the next one in three minutes.

To get ideas of what to build, I looked at the apps on my phone. I use my notes app every day, so I thought, "how about a better notes app?"

You can also ask your AI for ideas for apps. Ask, “Give me ideas for apps for my phone.” This can be business tools, productivity, personal, home, fun stuff, games, whatever.

Type this prompt in your AI:

  1. Before you start, read the following and say you understand.
  2. Your role: Act as an AI software developer.
  3. Your task: Provide the source code in a single file for a mobile website.
  4. Description of the task: Make an app for a simple To-Do-List. Keep track of tasks and mark them as complete.
  5. Features include add new tasks, mark tasks as complete (e.g., with a checkbox), delete completed tasks, allow reordering of tasks, add due dates.
  6. Suggest additional useful features for my app.

That's the basic prompt. Make changes to make your own app.

The AI writes the code

The AI will generate the code. It could be very long (mine was 12 pages). You don't have to read it. Just copy it.

The app code generated by the AI

Click the button at upper-right corner to copy the code.

Save it as a text file (babysfirstapp.html or whatever.html).

How to get the code to be an app

  1. Find the file on your computer. Double click it. Your app will open in your browser. Cool! It works!
  2. If you have a website on a server (such as I do at andreas.com): Upload the file babysfirstapp.html to your server. Don't create an HTML page that has HTML code on it and add the app code into it. The page should be just the app code. Don't use spaces in the file name, such as “babys first app.html”. If your text editor offers UTF encoding, use that when you save the file. Open it on your computer or phone. Open your browser and enter the URL of your website and the file name, such as andreas.com/babysfirstapp.html. Bingo, it works!
  3. If you don’t have a website: Set up a free website at NeoCities.org. Create your site, such as babysfirstapp.neocities.org. When the NeoCities file selector appears, either click Upload and upload your file (babysfirstapp.html) or drag your file babysfirstapp.html from your computer to the file selector. Go to your browser or phone and visit https://babysfirstapp.neocities.org/babysfirstapp.html. (replace with your URL and your app's file name).
  4. Show your mom what you did. Definitely deserves ice cream.

You can see my app at Baby's First App.

(BTW, your AI is non-deterministic, but it created your app’s code so your app is deterministic; that means it won’t have hallucinations.)

The app works on desktop computer and on Android or iPhone.

How to put the app on your phone

This is a web app, not an Apple Store/Play Store app. You don't install it from the app stores. The app runs from a webpage.

To put the app on your phone:

  1. Open the app from its web URL (such as Baby's First App.
  2. On Android: Click the three dots at at the right top. Select "Add to Home Screen". A web page icon is appears on your screen. Click it to open the app.
  3. On Apple iPhone: Click the share icon (square with an up arrow). Select "Add to Home Screen". A web page icon is appears on your screen.
  4. Your app is now on your phone.

My app has several features:

  • You can drag-and-drop to rearrange tasks.
  • Tasks are unique to each device: you can’t see my tasks and I can’t see your tasks.

Ask your AI for more features:

Describe your app to your AI and ask it to suggest more features. For example, my app could add the following:

  • Task Editing: Allow to click on a task to edit it.
  • Priority Levels: Add options to set task priority (High, Medium, Low) with visual indicators (colors, icons).
  • Subtasks: Allow subtasks under a main task.
  • Filtering: Add options to filter tasks (e.g., show all, active, completed, by due date).
  • Sorting: Allow sorting tasks by due date, creation date, or priority.
  • Reminders/Notifications: Integrate with browser notifications to remind users about upcoming due dates (requires user permission).
  • Tags/Categories: Assign tags or categories to tasks for better organization.
  • Themes: Offer color themes (dark mode, light mode).
  • Search Functionality: A search bar to quickly find tasks, especially useful for long lists.
  • Recurring Tasks: Ability to set tasks that repeat (e.g., daily, weekly).
  • And more...

"Look, Ma! No hands!" Build an app entirely on your phone. No computer.

One day, I wondered if I could do this entirely on my phone. No computer or laptop. Yep, it works!

  1. Open your AI on your phone.
  2. Type the prompt to make an app (see above, The prompt for your AI). Tip: keep it simple for the first one.
  3. Your AI will write the code.
  4. Sometimes, my AI will write the code in three files. You need it in one file. Tell the AI, "Rewrite this in one file."
  5. Copy the code. At the bottom of your AI, there's a COPY button. Copy the file. bu
  6. Open a text editor on your phone. It's possible your phone may not have one, so go to your app store and search for a text editor. I installed Simple Text Editor (it's for Android, free, and no ads).
  7. Paste the code into the text editor and save it, such as myapp.html (Don't put spaces in the file name. Use .html as the extension.) Save the file in documents so you can find it.
  8. Open your file browser on your phone. Find the file and click it.
  9. Your app will open.
  10. Add it to your phone's main screen.

Closing notes

  • If anything isn't clear, or it doesn't work, let me know and I'll fix it.
  • Try the different AI (Gemini, ChatGPT, Copilot, Claude, Deepseek, etc.). They produce different results. Some look better than others, some work, some don't.
  • If you have children, nieces, or nephews (or a very clever cat or dog), show them what you did. Give them this page. They can make apps.
  • Did you make something cool? Let me know. Make a screenshot of your app and send me an email to andreas@andreas.com