When it comes to editing images online, there are quite a lot of them available including the popular Aviary image editor. Not everyone can afford the expensive Photoshop, so you need to rely on other desktop alternatives or online image editors. Online editors have the advantage that you can edit images without having to install anything on your PC and perform the edits from any PC.
If you are looking for an online image editor, you should definitely be trying Picozu, an awesome editor with tons of features and a beautiful UI. The good feature of Picozu is that it allows users to connect with social sites like Facebook and cloud services like Dropbox, Google Drive or SkyDrive to retrieve the images and share them.
If you want to add a new image for editing, there are quite a lot of options to import them. You can use an image URL, browse from your PC or upload from social sites or cloud storage services. The web app has all the basic image editing like crop, rotate, cut, copy and other basic adjustments.
For advanced users, you get layers (similar to Photoshop) and other advanced tools. You get pretty good options to manage the layers as well. There are quite a lot of filters available within the app to apply on your image. You can also upload the edited photos to Facebook and other sites from the app.