Doodle.ly is a fabulous app for doodlers who like to share their spontaneous art with others. It launched in early 2012 as an iPad app, the most common canvas for those who like to draw, but it was lacking an iPhone companion app until now. The latest update to the app (version 2.1) brings a new iPhone version, native support for Tumblr and some UI tweaks.
Doodle.ly is a sketchpad app with the standard set of drawing tools including pens, pencils, crayons, highlights, markers, and a resizable eraser. You can draw freely on your iOS device and then save the drawing to your photo gallery or Doodle.ly's online gallery. You can also send it to a friend via email or MMS.
Doodle.ly is social and ties into a variety of social networks. It pulls in content from the Doodle.ly gallery, where you can browse other people's creations and follow them as a friend if you enjoy what they draw. There's also support for sharing on Facebook, Twitter or Tumblr (must have Tumblr app installed on your device).
Doodle.ly is available in the iOS App Store for free.