Both the fork version and the Pro version allow you to do that via the content editor when the rich content editor is enabled.
The fork uses the standard Image Library for WordPress which allows multiple file selection but is a bit of a minefield when adding captions unless you know what you are doing. Presently there is a bug where once the resultant gallery is added it can’t be edited in WP3.5.1.
The Pro version presently only allows one image at a time to be added (but multiple images can be added). Each image then can have it’s caption altered by clicking on it and the resultant edit icon. In time Tareq(the Frontend developer) will probably add to the Image capabilities of Pro as I have given him pointers in that direction.
None of the above options are great but there are heaps of plugins that specialize in this and your probably better off using one of these in combination with Frontend to get exactly what you are looking for.
TheProfessor
UPDATE: Actually the bug I mentioned in the last post for the fork only exists for WordPress 3.4.2 and maybe earlier. It works fine for WordPress 3.5.1. It’s also easy to use for adding captions.
