Low Latency Audio. Cross Platform on Android, OSX and iOS. Free.
Android's 10 Millisecond Problem Mobile Audio Latency Test App Android Audio Player USB Audio and MIDI for Android
In October of 2003, Apple introduced Core Audio as part of OS X 10.3, Panther, the fourth major release of Mac OS X. Though Core Audio handles all aspects of audio on iOS and OS X, it also serves as Apple’s audio API, providing developers with software interfaces for implementing audio features exclusively for iOS and OS X applications. Core Audio includes implementation of the cross-platform audio API OpenAL (Open Audio Library) as well, which models and plays audio in 3D space. Though once available as open source software, since OpenAL v1.1 the software has been proprietary.
Core Audio is designed to handle multiple channels of high bit rate floating-point digital audio, including low latency playback and manipulation. Because of Core Audio’s ability to render low latency audio better than Android, iOS devices and apps are somewhat more popular choices for musicians, audio professionals, and other users in need of real-time mobile audio processing.