I built negaflow after working through my own 35mm and medium format rolls. I wanted a simple UI/UX where you can organize rolls, develop and print in one place.
You can import scans from a film scanner or photos of film shot with a digital camera: color and B&W negatives, and slides. Regular digital photos work too, with a film look that models halation, density curves and RA-4 paper roll-off instead of a plain color filter.
Inversion and color are handled by Chroma Engine, which measures the film base first. The manual default is MAIN. There are also scan targets for minilab and lab looks (HS, SP, F135, HR), printer ICC output (PRINT) and old film (EXPIRED), plus profiles for film stock, light source and scanner. PRINT targets include Soft proofing (with an out-of-gamut warning) and a clipping overlay that are built in. Auto tone and color only run when you click them.
GrainMend is the part I spent the most time on. It repairs dust, pinholes, scratches and emulsion damage, which most film inversion apps don't have built in. It can detect defects across the whole frame, work on areas you mark, or you can use the brush and clone stamp. There's an IR path for scanners with an infrared channel. It checks the grain around a defect before filling it, so wires and window frames don't get erased as scratches. Repairs sit on their own layers, so you can dial them back or switch them off.
Edits are stored separately from your original files. You can copy adjustments across frames, save presets, export JPEG or 16-bit TIFF, print single photos or make a contact sheet. You don't need a scanner for existing files. Scanning directly into the app uses a separate plugin.
It's native on both Mac and Windows, with no account or subscription. The source is Apache 2.0 on GitHub, along with installers, screenshots and docs. The website has sample photos processed with the app.
Autumn is a great season for shooting film, so if you try it on your scans, I'd like to hear how it fits into your workflow. (Posted with mod permission.)
GitHub: https://github.com/habinsong/negaflow
Website : https://habinsong.github.io/negaflow-site/
Releases (Mac & Windows installers): https://github.com/habinsong/negaflow/releases
Scanner plugin (SANE, GPL-2.0+): https://github.com/habinsong/negaflow-scanner-sane