ART Teknika has released a new convolution reverb app with over 100 impulse response files included. The app allows to import your own IR files (below there are several links where you can get if free). iConvolver is Aubiobus and IAA compatible so it is easy to implement it into your sound chain.
Where to find IR files?
Here is a collection of great places where you can download free impulse responses from hi-end hardware reverbs to weird halls and strange things like dustbin:
Also if you have Logic Pro X you can find IR files folder //Library/Audio/Impulse Responses and you'll find many files open in iConvolver or similar apps without any problems. BTW, Logic Pro has one of the best Impulse Response file libraries (there is unconfirmed information that they made a deal with Audio Ease - developer of $500 Altiverb convolution reverb plugin to use some of their files).