The most requested feature for SmartGo Books: bookmarks and/or notes. I had planned to tackle that later this year, but when Scott Jensen came up with an exquisite update for the app icon, I had no choice.
To add your own notes to any paragraph or diagram, just tap and hold on a paragraph (or diagram), then choose Add Note. To find your notes and navigate between them, tap on the move number at the bottom of the page, tap the bookmark icon on the right, then use the slider to go from note to note.
The user interface is very minimal at this point. I anticipate adding more support for notes in future versions, once I know better how you actually use them. Please let me know what you’re missing. Notes are not yet synced between devices, that’s definitely on the list.