I've searched a ton of image editors -- all I want to do is adjust the image levels -- brightness, saturation, exposure are all perfect! The "Extended Image" edit is an additional button next to "Edit Image" under "Edit more details" -- so you can still use the built in Edit / Crop.
I would strongly urge the original developer to fix the save issue and continue working on this. The implementation is simple & effective in extending the existing image adjustments that are possible right in the Media section.
If you can fix the processing image... save issue, I'll come back and rate this as 5 stars.
EDIT: So .... I tried another image -- and the "processing image" worked without issue; however, it doesn't actually update the image in the Media.
BUT ... there is a simple workaround -- after making your Edik edits, click the built-in "Edit" and make a meaningless change -- e.g., select full image and click crop, then Save ... the changes will take effect. That's good enough for me -- I'm bumping my rating up.
DEVELOPER: PLEASE KEEP GOING ON THIS -- DONT' GIVE UP.