Good news if you’re a fan; Notify by Underscore has received a significant update this week. Among the many features added to the update are a completely rewritten rendering engine, improved support of Retina display devices, and a new user feedback website accessible from within the application. There are also many improvements and bug fixes.

For those who have never used Notify, it purports to be the only note app you’ll ever need. As described on its Web site:

Launch Notify and immediately start jotting down a reminder, write an essay, slice’n'dice a photo of a whiteboard, draw a diagram, type a bulleted list, build up a moodboard, scribble directions on a map, or read and annotate a lengthy document. Notify easily imports an extensive range of formats (including PDF, Word, Excel & Powerpoint and many more) either directly from an email or from files stored on cloud servers such as Dropbox™, Box.net™, Google Docs™, Evernote™, iDisk™, FTP or WebDAV.

Notify’s biggest strength is also its weakness: its staggering number of features. I was blown away by the depth and power of all the things you could do. This app is clearly a labor of love. At the same time, the interface can be daunting for a new user. There is a learning curve, which not everyone will be prepared to invest their time in. To its credit, the app does offer a number of helpful tutorial videos to show the way (please note that the tutorials have not yet been updated to reflect the changes in version 4.0, but the developer assures me that they will be).

For the casual user looking for a simple note-taking app, I would recommend sticking with an app like Penultimate or Bamboo Paper. For someone looking for more powerful features, Notify is worth a look.

Underscore Notify is a universal app and is available in the App Store now for $1.99.