digiKam - Professional Photo Management with the Power of Open Source
Dropbox - Online Sync and File Sharing
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Google Drive - Access and sync your files anywhere
Photos on macOS - Photos keeps your images organized and accessible. Rediscover favorite shots with Memories. Access them on your devices with iCloud Photos.
Nextcloud - With Nextcloud enterprises host their own secure cloud solution for storage, collaboration & communication from any device, anywhere.