Workflow is one of those amazing apps that really shouldn’t exist on iOS. With it, you can do all sorts of automation things. Over on One Tap Less, they point to a few workflows that allow you to do things you’re definitely not supposed to do on iOS: download content from various apps.
Workflow essentially makes it possible to grab a URL, then download the content of that URL to your photo album. In most cases, this means selecting the “share URL” option in an app, then triggering the Workflow. Here are some examples:
Trigger Workflows with Clipboard Text as Input | One Tap Less