Gnaural is a computer-based audio synthesizer capable of generating binaural beats, isochronic tones, pink noise, and many varieties of simulated nature sounds (including rain, waterfall, ocean waves, babbling brook, and wind). Gnaural is intended to be an aural aid to meditation and relaxation. Long available for Mac, Windows, and Linux, Gnaural allows you to use your computer to create, edit, and play your own "presets" - which are editable meditation sessions coded in to XML text files.
Gnaural for Android is able to play Gnaural presets that you copy to your device, but can't edit them beyond the ability to turn on/off individual voices, specify number of "loops" (times to repeat the preset), and manually move forward-and-backward through the schedule. However, Gnaural presets, being simple text files written in Gnaural's XML language, can be edited by hand with any text editor and then opened by Gnaural for Android. The only issue you might run in to is that if your preset uses external audio files - in which case Gnaural for Android can only play external CD-quality WAV audio files, not the many formats open-able by the full computer-based Gnaural (such as FLAC and OGG). This should not be a real limitation, as any audio format can easily be converted to WAV using readily available software like Audacity.
For people not interested in playing external Gnaural presets, Gnaural for Android also comes with 14 built-in presets, designed to explore a range of mental states with binaural beats and isochronic tones, as well as providing a range of soothing background sounds (like water or wind) that can be played continuously to help one relax or sleep.
Unlike most audio players, Gnaural for Android is a true sound synthesizer, creating and mixing CD quality sound on-the-fly from user-programmable instructions without relying on any sound files. Generating live synthesized sound requires a lot of processing power. Most cellphones less than 2 years old should have enough horsepower to run basic presets. If you do experience stuttering, such as when processing complex multi-voiced presets, there are options to lower the processing load by either lowering the sample rate (under Preferences), or by turning off extra voices. It is strongly recommended that you use and get-to-know the free version of Gnaural well first before deciding to pay to support this version. The free version is available here: