iAnnotate, a powerful annotation application for the iPad was updated today to version 2.4.5.
The current and prior updates include:
-Support for built-in iOS dictionary (offline dictionary)
-Support for higher resolution image* import and annotation
-A variety of stability improvements for users of cloud storage services
– Sync with Google Drive and Microsoft SkyDrive
– Support for viewing and marking up image files*
– Updates to Dropbox connectivity
– WebDAV connects with a wider array of servers
– Stability enhancements
This app can be used to read and mark up PDFs and other documents.
iPad Notebook 
Hello. Have you ever tried writepdf? its not dissimilar to this app and lets me inline edit my docs on the ipad