This is a high-fidelity prototyping tool designed to be used directly in your Google Drive. I found this last semester when I was looking around for a better alternative to Google Drawings for sharing prototypes. Unfortunately, unlike Google Drawings, your collaborators can’t see changes in real-time. On the other hand, it’s very handy if the group is already using Google Drive like we do at work.
ProtoShare, like many other prototyping/wireframing tools has a number of commonly used web page elements, including form controls, images, and other structural elements. All of these start out with sane default formatting, but can be customized as needed. Form controls are interactive, eg. select elements behave as expected.
For interactive prototypes, the individual elements can be assigned actions that fire when the element is interacted with.