Snip&Sketch - Quickly annotate screenshots, photos and other images with your pen, touch, or mouse and save, paste or share with other apps.
Flickr - image and video hosting website
NinjaCapture - All in on Screen Capture
Imgur - Imgur is a free and simple image hosting service with image editing feature. Signup is optional.
Picosmos Tools - Picosmos Tools integrates picture browsing, editing, layout, frames, and cosmetic effects into one set. It also provides plenty of source material.
PhotoPrism.app - PhotoPrism® is an AI-Powered Photos App for the Decentralized Web. It makes use of the latest technologies to tag and find pictures automatically without getting in your way. You can run it at home, on a private server, or in the cloud.