digiKam - Professional Photo Management with the Power of Open Source
Prisma - Art filters using artificial intelligence to transform your photos into classic artwork.
Photos on macOS - Photos keeps your images organized and accessible. Rediscover favorite shots with Memories. Access them on your devices with iCloud Photos.
Visionn - Real-time artistic photo and video effects
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Photolemur - Photo enhancement on autopilot