At the Nokia Developer Summit today, Nokia unveiled a number of major improvements in its developer tools, including "significant enhancements to the Nokia Qt (SDK), resulting in a 70 percent reduction in the number of lines of code required when developing for Symbian", improvements to the Ovi Store "including a new look and feel, making it faster and making apps easier to find", plus a "lower barrier of entry and increased monetization opportunities for developers, including free Java and Symbian signing, in-app purchase, improved revenue share, and advanced developer analytics".

From the press release:

Today, developers can distribute apps to approximately 175 million Nokia Symbian smartphones - the largest smartphone user base in the world. Qt is pre-installed on all new Nokia smartphones and downloadable to millions of smartphones people are already using. Using the Nokia Qt SDK to build their apps, developers will discover a complete, easy-to-use tool that brings a shortened workflow, simplified development and intuitive UI libraries resulting in 70 percent fewer lines of code, cutting creation time dramatically.

New opportunities for developers will include in-app purchase, enabling a wide range of app pricing options in Ovi Store such as subscription models, micro-transactions, or "try and buy." This means if people enjoy the free version of the app, they can easily upgrade to the paid version. It also allows developers to build added value into their apps such as the sale of virtual goods, additional levels for games, or enhanced or localized in-app features. 

Mikael Hed, CEO of Rovio, the company behind one of the world's most popular mobile games, Angry Birds, is pleased to bring the game to Nokia devices. Speaking about the new in-app purchase feature in Ovi Store, Hed said, "We now have an elegant mechanism for providing premium content within games, like Angry Birds, in a way that doesn't interrupt people playing the game." (The example of the 'Mighty Eagle' was quoted)

With the Nokia Qt SDK, developers can also future proof their app by easily adapting them to run on future mobile platforms such as MeeGo, while taking advantage of any additional features or APIs those platforms bring.

Nokia will focus on making developers more money by leveraging the largest operator billing footprint available and greatly improving the operator revenue share for payments made after October 1. Nokia has also removed the time consuming and costly step of app signing. With one click, Java and Symbian apps signing is complete.

There's more on Qt SDK 1.0 here.

Angry Birds for Symbian is coming shortly, along with other applications that support in-app purchases.