Pixcavator Single Image Edition
This edition is a version of Pixcavator that comes with a preloaded image. Which means that it's not really a single program but many - one for each image.
It is a single file "exe" program that does not require any installation. As such it can be used as an alternative to screenshots, for demos, etc.
This edition has all the features of the standard edition except for image processing tools. This way you can choose different color channels for your analysis, experiment with the sliders, and save your work.
Some of the image analysis examples have links to the corresponding files. For a start, try to run these two examples:
In FF: choose "Save", then "Run". In IE: just choose "Run".
This how we can get as close to web app without actually creating it.