From an idea to your first app with First.new
Start with a small idea, test the preview, and improve it one conversation at a time. A practical walkthrough using a personal reading list.
A small app is a useful first step
You do not need a complete specification to start building an app. You need one person to help, one problem to solve, and a way to tell whether the result is useful. This guide walks through a small example: a reading list you can use, improve, and share.
Start with one useful thing
For this example, the goal is simple: save books you want to read and see which ones you have finished. Resist adding a social feed, recommendations, or a marketplace to the first version. Those ideas can wait until the core flow works.
A useful first prompt describes the person using the app, the action they need to take, and the result they should see. Include a few concrete details so the first preview has something to work with.
Read the preview like a user
Enter your prompt in First.new. The builder puts the conversation beside an app preview, so you can inspect the result as you work. Give the first version a practical test: add a book, change its status, and filter the list. Then try a long title and an empty list.
A convincing screen is only part of a useful app. Check whether your changes survive a refresh, whether the controls behave as expected, and whether the layout remains usable on a small screen. If something fails, describe the exact action and what you expected to happen.
Use sample information first
Make one focused change
Your next prompt can be much smaller than the first. Ask for one change, inspect the updated preview, and repeat. A specific observation gives the builder more to work with than “make it better.”
Use this loop for both design and behavior. If you want a different layout, name the part you want to change. If a button does not work, describe the steps that lead to the problem. After every change, revisit the original flow so improvements do not hide a regression.
Check before you share
| Check | What to try |
|---|---|
| Core flow | Add a book, edit its status, and filter the list. |
| Persistence | Refresh and confirm whether the app keeps the data you expect. |
| Small screens | Check long titles, scrolling, and tap targets on a phone. |
| Empty states | Try an empty list and missing fields. |
| Access and privacy | Confirm who can view or change any saved information. |
When the current version behaves as expected, use First.new’s publishing flow to create a shareable link. Open that link in a fresh browser session and repeat the core flow. The shared version deserves the same checks as the preview.
Let the first version teach you
Share the app with someone who would use it. Ask them to complete one task without a walkthrough, then watch where they get stuck. Their feedback will give you a more useful next step than a long list of speculative features.
You can start with a reading list, a tracker, or another small tool you wish existed. Keep the first goal concrete, check the result, and improve it one conversation at a time.