IrfanView - IrfanView ... one of the most popular viewers worldwide.
digiKam - Professional Photo Management with the Power of Open Source
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Photos on macOS - Photos keeps your images organized and accessible. Rediscover favorite shots with Memories. Access them on your devices with iCloud Photos.
Scheduler - Scheduler – Schedule Posts for Instagram, Facebook developed and published by Scheduler Inc.
Facebook Pages Manager - Learn how to manage your Facebook Page and discover all the available tools that give you control over your business Pages.