QuincyKit is a feature-rich toolkit that collects crash data from your OS X / iOS applications.

On the client side, QuincyKit provides a way of sending crash reports to your database, giving the user a choice of whether or not to do it.

If the error is known, the user is notified about the status of the fix; the user can also leave his contact details, etc.

On the developer side, QuincyKit’s admin interface can automatically sort crash data, maintain the crash reports, and assign the progress of bugfixes.

QuincyKit looks like it could become an important cool for any serious Mac/iOS developer.

Three20 is an Objective-C library for developing iOS applications.

The library is open-source, and very popular — it’s used by app store giants such as Pulse, Meetup.com, Facebook and others.

Three20 is regularly extended by the community, with free extensions available for any taste.

Three20′s functionality is outstanding and, enhanced by the powerful view controllers employed by this framework, makes for a surprisingly solid, and reliable coding environment.

Tapku (tap+haiku) is an open source iOS framework built on Cocoa and UIKit.

Overall, Tapku is a very comprehensive framework that pretty much works wonders when used correctly.

However, although Tapku offers native solutions to common problems (calendar, graphs, etc.), it isn’t a panacea for iOS developers as a lot more ground isn’t covered (data storage?).

PadCMS is a new open-source content management system for publishing tablet-oriented magazines.

The developers promise support for PDF, HTML, pictures, video and audio.

If you plan on running a web-based magazine (or plan on ‘porting’ it to the iPad), stay tuned for PadCMS

The one thing that PadCMS is missing as of now… is a download of the CMS; however, the release date will surely be soon enough.

TapLynx is a framework for developing iPhone apps.

Features include:

• Native video playback
• Audio streaming
• Offline content storage
• Easily implementable sharing
• Easy monetization

We don’t really like the license, though: it’s free to evaluate, but if you actually produce something for the Apple store, you have to buy the enterprise edition, which costs $599.

The money shouldn’t be a hassle if you’re confident that your app will perform well.

Do check out PhoneGap or iWebKit if you want a free mobile framework for developing simpler apps.

Sparrow is an Objective C framework used for developing games on iPhone.

Sparrow is made in a way that allows completely skipping OpenGL coding–unless you really want to switch.

The framework’s main features are:

• Intuitive coding and easy to learn (Flash, Java, etc developers will love this!)
• Great performance (Sparrow can animate several hundred textured quads at 50+ fps)
• Numerous projects have already been developed with Sparrow (see ‘in action’)