Flashdays: your camera roll, developed like it's 2006

In short

Flashdays takes up to 20 photos from the camera roll, applies the same camera body to all of them and exports the set as a carousel, in the order the user chose. The look comes from a fragment shader we wrote that runs on the phone's GPU, so no photo is uploaded and no face is altered. We designed and built the app in Flutter for Android 8+ and iOS 15+, in 10 languages. The screens on this page come from a test build with painted synthetic scenes, not real photos.

Client: Flashdays · Photo app
Sector: Consumer photo app
Where: Bogotá, Colombia
Year: 2026
Deliverables: Flutter app for Android and iOS
GPU darkroom shader
Recipes synced to an optional account
Onboarding, Pro subscription and settings
10 languages, Arabic RTL included
Services: Mobile apps
Digital products

42camera bodies in version 1.1

20photos per roll

10languages

The context

The compact-camera look, without buying a camera

Photo dumps and carousels on TikTok and Instagram borrowed the look of mid-2000s compact cameras: hard flash, cool CCD colour, grain and a date printed in the corner. Getting it meant buying a used camera and moving files around, or editing photo by photo in apps that are often iOS-only, English-first or paywalled before they show a result.

Some of those apps run AI filters that change faces, or overwrite the date the photo was taken. We set three rules for Flashdays: one look for the whole roll, the real capture date on the stamp, and photos that never leave the phone.

Design and build

A darkroom on the phone's GPU

Each camera body is a set of parameters for a single fragment shader: exposure, contrast, colour temperature, flash falloff, bloom, vignette, grain, chroma noise, sharpening and split toning. The editor previews the chosen body live on the current photo, and holding a finger on the photo shows the original. Flash, date stamp (the day the photo was taken, today, none, or a retro year from 2000 to 2012) and frame (4:3, 4:5 or 9:16) apply to the whole roll.

Developing runs every frame through the same shader, encodes it as a JPEG with the EXIF metadata stripped, and hands the carousel to Save to Photos or the share sheet in the order the user set. Photos come in through the system picker, so the app never asks for the whole gallery; camera and add-to-Photos permissions are requested only when those buttons are tapped. The free version develops full carousels of up to 6 photos with a watermark. Pro removes it, exports at full resolution, raises the roll to 20 photos and unlocks more bodies, retro years and recipes.

Recipes save a combination of body, flash, stamp and frame, and they are the only feature that touches a server. The first time a Pro user opens them, the app quietly starts a guest session; signing in later with Apple or an email code moves the recipes, up to 50, to that account. The account can be deleted from Settings.

Pick photos, try camera bodies, develop 6 photos and swipe through the carousel. Test build with synthetic scenes.

01
One look for the whole roll

Pick up to 20 photos and one camera body, and every frame is developed the same way before it leaves as a carousel in the order you set.
02
The real date on the stamp

The orange stamp prints the day each photo was taken, read from its EXIF data, or today's date, or the same day in a year of the digicam era.
03
Nothing is uploaded

Picking, developing and exporting happen on the phone. Exported JPEGs carry no metadata, and the only thing on a server is the recipes of people who save them.
04
Hold to see the original

The editor shows the developed photo live; a finger on it brings back the original, and the strip tries each body on the current photo.

Gallery

The project in pictures

8 images · Open any image to see it full size.

Onboarding: the demo photo cycles through the camera bodies (8 in version 1.0). No permission or account is asked for.

Home: pick photos or take one, then choose a camera body to start a roll.

The editor with Party Flash on a 6-photo roll: live preview, the camera-body strip, flash, date and frame.

The same roll on another photo. Each thumbnail in the strip previews its body on the current photo.

Date stamp options: none, the day each photo was taken, today, or the same day in a retro year.

The developed roll in carousel order, with Save to Photos and Share the carousel.

Recipes synced to an account: body, flash, date and frame saved under a name (sample recipes).

The editor in French. The app is in 10 languages, right-to-left Arabic included.

Outcomes

From version 1.0 to 1.1

Version 1.0 has 8 camera bodies and the editor shown on this page. Version 1.1 grows the catalogue to 42 bodies, 21 of them free, moves the controls into a tabbed panel (camera, effects, frame, date, tune) so they never cover the photo, and adds a contact sheet that puts the whole roll on one image. Recipes in 1.1 store every option, and older versions ignore the fields they don't know.

The app has 65 automated tests, six of them on the real shader: they develop a generated photo and check that the JPEG carries no EXIF. Home and the editor are tested in right-to-left Arabic and with text at 200 %, and Home in dark mode as well.

42 camera bodies in version 1.1, 21 of them free
10 languages, including Japanese, Korean, Chinese and Arabic
Android 8+ and iOS 15+, works offline except for recipes
Screens and video: test build, painted synthetic scenes, no real photos or people

Frequently asked questions

The questions we hear often

Does Flashdays upload my photos?

No. Photos are picked with the system picker and developed on the phone's GPU. They only leave the phone when you save them to your gallery or share them with an app you choose.

Does Flashdays use AI on faces?

No. The look is a shader that changes colour, light, grain and flash evenly across the whole image. It does not detect or alter faces.

Is the date on the stamp the real one?

By default, yes: it is the day each photo was taken, read from its EXIF data. You can also use today's date, turn the stamp off, or pick the same day in a year between 2000 and 2012.

Next case study Amanda McLane Attali · PEPS English pronunciation, spelled in French sounds

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