MyDropzone replaces MyBB's default attachments behavior with a reliable drag and drop solution (Dropzone.js) which uses AJAX instead. Uploading an attachment becomes extremely easy and fast.

MyDropzone adds 1 stylesheet and 3 templates which overwrite the default ones during runtime. Existing templates are not edited nor deleted.

Minimum requirements
PHP 5.4
MyBB 1.8.0

Features
MyDropzone does not come with many complicated features other than being a neat replacement for the attachments box, and that's pretty much it. MyDropzone inherits all the existing attachments features – except for approving/unapproving, which is not available in the current version. A special mention goes to Imgur.com support which lets your users upload images anonymously to Imgur.com and the generated URL will be added to their messages as soon as the upload finishes.

Quick reply attachments
MyDropzone adds support for posting attachments from quick reply. However, it does not edit any templates, so in order to use this functionality you need to alter templates by yourself. This decision was made because in the past, many lamented that a particular functionality in other plugins was not working while they were using a custom theme and the search and replace routine was not able to find the associated pattern.

If you want to enable your users to post attachments from quick reply, edit your showthread_quickreply template, and add the following variable wherever you want the box to appear:

{$attachbox}

This loads nothing but the post_attachments template as it does in New Reply, New Thread, Edit Post, etc.. Once you style the attachment box, quick reply automatically inherits the same styling.

Multiple attachments simultaneously
MyDropzone supports uploading multiple attachments at the same time. Just drag and drop how many attachments you want to upload, and it will handle all of them at once till the maximum limit (which inherits from the attachments system settings) is reached.

This feature is also available on stock MyBB 1.8.19 onwards.

Imgur.com support informations
How to get the Client ID
In order to upload images to Imgur, you need to enter a Client ID in MyDropzone settings, otherwise the plugin will fall back to default server uploading.

If you do not have an Imgur.com account, register for free and go to this page to create a new application. Fill the informations and select Anonymous usage without user authorization under Authorization type.

When you have finished, go to this page and copy the Client ID, add it to MyDropzone settings and enjoy.

Rate limits
Imgur.com limits their API usage to 1250 uploads per day. Although this should be ok with most of MyBB boards out there, if you are running a big board (100k+ users) you may want to switch to normal image handling. For more informations on limitations imposed by Imgur.com, visit this page.

Notice under the attachment box
Due to the fact that MyDropzone does not edit templates, I have added a notice to the mydropzone_attachments_new template informing users that their images are posted to Imgur. If you are not willing to use this feature, delete the corresponding HTML you can find in the template.

Customization
You can completely customize MyDropzone's appearance by tweaking with its templates (MyDropzone Templates Group) and its stylesheet (mydropzone.css). Support will be given when possible.

Compatibility
MyDropzone is compatible with MyBB 1.8.0+ and PHP 5.4+. Browser compatibility is listed on Dropzone.js documentation.

Credits to Shade at MyBB Boost - https://www.mybboost.com/thread-release-mydropzone-1-2