Tweetot for Twitter 2.7.1 ($3) - Tweetbot is a Twitter client that includes multiple timelines, smart gestures, and support for a number of other social services such as Instapaper and CloudApp. Following the recent v2.7 update that introduced a new browser setting for specifying an external app for opening links, the latest release addresses a crash that could occur during startup. [Download - 11.1MB]

Amplitube 2.9 ($20) - Amplitube is a guitar amp modelling app that can be used to play, practice, and record. The software includes a built-in four track recorder, as well as a variety of amp models and effects for capturing different tones. New to v2.9 is Loop Drummer, a new feature that lets users practice over single loops or entire drum sequences. Custom sequences, complete with intro, groove variations, fills, and an ending, can be created directly within the app by simply dragging the various loops into a timeline. [Download - 235MB]

Drafts 2.5.2 ($3) - Drafts for iPad is a text editor that allows users to quickly take notes and choose where to send them later. Version 2.5.2 improves the app's launch time and addresses several sync issues, including one that prevented drafts that were deleted offline from syncing when reconnecting to a network. A new Courier Prime font is also included along with various other bug fixes. [Download - 6.6MB]

Penultimate 4.0.1 (free) - Penultimate is a note taking app that lets users create handwritten notes on photorealistic paper templates. Full iOS 5 support is included in this release, along with a fix for a crash some users experienced when launching the app. Additionally, Evernote integration has been improved, including full sync support and the ability to use Evernote's handwriting search feature. [Download - 41.9MB]

Projectbook 1.3 ($2) - Projectbook is a notebook app that can store notes, to-do lists, Word docs, web clips, sketches, and more. Version 1.3 expands the apps feature set with enhancements to sketching, similar notes, and e-mailing. Sketching and handwriting within the app should now be faster and more responsive, while the app's natural language processing is said to be more accurate. Additionally, Word documents and PDFs can now be e-mailed directly from within Projectbook. [Download - 29.4MB]