This plugin search for images in the content of posts and upload it automatically.

imanabuhaydari

Iman Heydari

This plugin functionality happens when you want to save a new post, it searches for external image links, and uploads them into your site, then attaches the images to the post. 
This plugin is so light and has been written with the least codes, So it does not decline your site speed.
You can set the first image as a thumbnail, while uploading.( Please turn on the related switch in settings page )

Automatic Image Uploader

A useful and simple plugin

The plugin works, but version 1.3.1 has drawbacks: 
1) The unloading process breaks down when phrases like "$70/month" are found in the post text (wp_extract_urls sees this as a url, processing $urls causes an exception). 
2) Does not work correctly with urls having parameters.

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