BeFunky connects to all of your online social networks and photo sharing sites and it lets you easily edit, crop, resize and apply a ton of effects to any photo or image you have.
Ribbet is a free web-based image editor which offers lots of ready-made Instagram-like effects, photo collage options, resizing, cropping and more editing features.
PIcfull is a free photo-editor which allows you to upload your own images and add effects to them.
Fotor is an outstanding web-based image editor integrating a unique toolset to create stunning photo-montages, image boards, strips and photo cards. It connects directly to Instagram, Facebook, Flickr, Picasa and more. Free.
Photoshop Express - all of the basic image editing enhancing tools from the king of image editors - free - online
SplashUp is an advanced web-based image editor and photo-manager supports layers, multiple image editing and connects directly to Picasa, Flickr, Facebook
Ipiccy - free web-based photo editor - ad-supported - good functionalities and ease of use
Citrify - Flash-based all round online image editor
Photozoe - All of the original Aviary tools under a different brand
PicMonkey - Supereasy, highly visual and simple to use web-based photo editor
Pixlr - Three editors one software - excellent toolset, speed and ease of use for all types of users with Pixlr
FotoFlexer is the most powerful online photo editor in existence. It can remove blemishes, change skin/hair color, morph photos and more! 100% free.