Coming Soon to iOS

Develop film with confidence.

A guided timer app with audio agitation cues, chemistry tracking, and exhaustion-compensated development times. Built for home darkroom photographers.

Join the Waitlist See the App

Free tier included. No credit card required.

The Problem

Developing at home shouldn't mean guessing.

Kitchen and phone timers don't know your agitation intervals. Printed instructions don't automatically adjust for exhausted chemistry. And forgetting which roll you're on means inconsistent results, or ruined film.

Film Development Timer replaces all of that with a single guided workflow.

Features

Everything you need. Nothing you don't.

Guided Step-by-Step Timer

Walk through all developing steps depending on your chosen chemistry kit with color-coded timers. Each step auto-advances or waits for your tap.

Audio Agitation Cues

Distinct audio tones tell you when to agitate, when to wait, and when inversions are coming. You can look away from the screen if you wanted to.

Chemistry Batch Tracking

Track multiple chemistry batches with mix dates, roll counts, and expiry warnings. A health bar shows remaining capacity at a glance.

Exhaustion-Compensated Times

Development time automatically increases as your chemistry is used. No mental math. The app adjusts for volume and roll count.

Push/Pull Processing

Select -1 to +3 stops and get the correct development time instantly. Supports variable temperature development from 72°F to 102°F. *Currently modeled after Cs41. Support for other kits coming soon.

Film Stock & Chemistry Kit Library

Built-in library of popular stocks from Kodak, Fujifilm, CineStill, and Lomography. More chemistry kits will be supported based on community feedback.

App Preview

See it in action.

Your film development command center.

See your active chemistry status, development chart (push/pull, temperature, dev time, and agitation), and total process time at a glance. Just choose a film stock to start developing.

Precision timing with audio cues.

A large monospace timer with a timeline and agitation instructions. Different types of audio ticks keep you on track, even when you're far away from your phone.

Manage multiple batches.

Managed chemistry quality = good negatives. Track which batches are expired.

Roll complete. Every detail logged.

Film stock, format, ISO, and notes at a glance. The batch roll count updates automatically, with a warning when it's time to mix fresh chemistry.

See more screenshots

How It Works

Three steps to perfect development.

  1. 1

    Select your chemistry & film

    Choose your active batch and film stock. The app shows your chemistry health, session time, and any warnings before you start.

  2. 2

    Follow the guided timer

    Audio cues tell you exactly when to agitate. The timer handles exhaustion compensation, push/pull adjustments, and step transitions.

  3. 3

    Log and track

    Every roll is recorded with film stock, format, and processing details. Your chemistry batch updates automatically.

Try It

See how dev times are calculated.

Adjust push/pull, volume, format, and roll count to preview exhaustion-compensated development times.

Developer Kit

More developers and chemicals coming soon.

Developer Temperature

Push / Pull

Chemical Volume

Film Format

Calculated Development Time

03:30

210 seconds

Base: 210s × Multiplier: 1.00
Push/Pull 0 rolls 5 rolls 10 rolls 15 rolls 20 rolls

Why Trust Us

Built by a film photographer, for film photographers.

This app exists because I got scared of ruining my precious rolls of film. I got tired of logging rolls on a piece of paper. Every timing value and workflow comes from manufacturer manuals.

Currently shipping with the CineStill kit built in, with more chemistry kits based on what you tell us you use.

Early Access

Get early access.

Join the waitlist and help shape the app. Tell us what chemistry and film stocks you want supported.

Film Dev Timer mascot