Build a photo editor, collage or scanner app (no code)

Photo utilities are small, focused and endlessly needed: an ID-photo maker for job applications, a document scanner that outputs a clean PDF, a collage maker for shop promos, a watermark tool for photographers. Each is a couple of screens and some image processing — which App Builder Agent handles on the device, without uploading anyone’s photos.

This guide covers the common photo apps, how to describe the processing you want, and the details that make them feel professional.

What photo apps need

Pick one job and do it cleanly. The basics shared by most photo apps:

• Pick or capture — Gallery picker and camera, with permissions explained in plain words.
• Crop, rotate, straighten — With aspect presets (1:1, 4:5, passport sizes).
• Adjustments and filters — Brightness, contrast, saturation, warmth, and a few named looks.
• Text, stickers, watermark — Add a caption or a logo; remember the last watermark position.
• Export — Save to gallery at a chosen size and quality; share directly to WhatsApp/Instagram.
• Batch — Apply the same edit to many photos — the killer feature for shops and photographers.
• Privacy — All processing on the device; say so on the first screen.

Build it with App Builder Agent, step by step

Describe the job in terms of input, steps and output; the agent picks the image tools.

1. Create a mobile app project. Camera, gallery and file export need a native app.
2. Describe the workflow. Input → processing → output, with the sizes or formats you need.
   Build a document scanner app called Sheaf. Capture with the camera or pick from gallery; detect the document edges and let me adjust the corners; perspective-correct; enhance (black-and-white, colour, grayscale); combine multiple pages into one PDF; name and save the PDF; share it; a library of past scans with search by name. All processing on the device. Clean white UI with a blue accent.
3. Scan a real page. Check edge detection and the PDF quality on a phone; tell the agent what looks off.
4. Add the extras. OCR to text, signatures, page reordering, compression levels.
   Add text recognition (OCR) to copy text from a scan, a signature tool to place a saved signature on a page, and drag to reorder pages.
5. Ship. Export the APK. This kind of app is often shared person to person; put a share button in Settings.

Prompts that work well

Photo apps people build:

Make it feel finished

• Process on the device and say so; photos are personal.
• Offer size presets for WhatsApp, Instagram and print — users don’t know pixels.
• Keep originals; write edits to new files.
• Batch mode is worth more than ten filters.

No servers, no uploads

Everything runs on the phone, so there is nothing to host and no privacy policy headaches beyond the basics. Export the APK and share it; a website version can handle simpler jobs like resizing in the browser.

Add features by describing the next job you want the app to do.

Frequently asked