It has everything you need to build your application, from code editing to debugging. I love that it's open source with an active community supporting its development. The UI is very intuitive but sometimes could be improved for new users like myself. Sometimes there are glitches in the IDE when using third party libraries. If you're looking for a stable cross-platform toolkit then this is what you should go for. We use Qt Creator at work as we develop apps across multiple platforms such as Windows, Linux and Mac OS X.