Thanks for getting back!
Basically I am creating a very basic form on the front end, which will submit a new post. Fields are post title, description text and images. Images should just be added by drag and drop, very much like your plugin and then be attached (NOT inserted) into newly created post.
Anyway, I will have a go at it tomorrow using the standard wordpress media manager to upload images. I just do not like it (media manager) opening another modal window, as ideally my form opens in a modal already. Just a simple field/image/box that says "Drag images here" would be enough. Better would be after you dragged the images to be able to delete, sort and choose featured image from images uploaded by clicking on some buttons that overlay each image.
That is my particular use case :)