Zero Reverb is an extremely good sounding Audio Unit Reverb that works as a plug-in inside host apps. Just open up your favorite host that supports Audio Units and add it as an effect. The controls expand when touched so they can be easily seen while tweaking. Zero Reverb will soon become your go-to reverb plug-in on iOS.
Picture above is from using MultiTrack DAW as a host.
Zero Reverb is a high quality Feedback Delay Network reverberator in the Audio Unit Extension format. The algorithm has rich feedback with smooth decay for a modern hall-like reverb character. Blamsoft brings their experience creating high quality plug-ins for the desktop to iOS. The same algorithm is found in the popular Zero Hybrid Synthesizer Rack Extension for Propellerhead Reason. The available parameters allow you to dial in a wide variety of reverb textures.