Welcome to the 99xApp website where you can get information for all things xApp !

Click on an icon for information on a xApp.

xApps are designed to do a specific job well with a minimum of complications. The user interface is intuitive, the workspace uncluttered. xApps are currently under development for three distinct areas.

1. Signal generation and processing :

2. Midi processing for gigging musicians :

3. Reading and spelling :
xWave turns your Mac into a signal generator, taking the place of an expensive piece of test equipment. It is most useful as a sine wave generator with calibrated output capability.
A variable sweep function allows testing of audio frequency response. Note that the Mac audio system does begin a high frequency rolloff at around 15 kHz.
A burst function is provided. From one to twenty cycles of a specified frequency and waveform can be selected.
In addition to the sine wave, other waveforms are provided. A disclaimer is warranted here. The digital audio frequency filtering - part of any digital to analog audio system - distorts the discontinuities of any waveform containing harmonics out of the audio range. The risetimes have been tweaked to minimize this distortion while maintaining sufficient harmonic content for audio system testing.
The DAC on a typical Mac is fine for most audio use, but does a poor job on square waves. An outboard USB-connected DAC will give a much better waveform.

xWave was developed for my use when I needed a second signal generator for my audio work and I didn’t want to spend another $500 for a dedicated piece of test equipment. I needed a clean sine wave and xWave provides this. For $2.99 !


Available at the Mac App Store.

xWave is effective, easy to use, and cheap ! It’s a xApp !


xVee gives you full control of the dynamic range of your keyboard. Originally designed for my Nord piano, it allows you use your own custom velocity curve.
To use the velocity function in xVee, simply connect your USB-equipped keyboard to your computer running xVee. Set your keyboard’s "LOCAL" midi parameter to "OFF". xVee will modify the velocity parameter and echo it back to your keyboard.
The latest version of xVee has a few enhanced features that are useful when using Mainstage or another software instrument:
Available at the Mac App Store.

xVee is effective, easy to use, and cheap ! It’s a xApp !

xSpell speaks a word and the student is asked to type it into the keyboard. Immediate feedback is given. Missed words are repeated until they are spelled correctly. If needed, a hint is provided. At the end of the lesson all words that gave the student trouble are repeated.
A selection of standard spelling words lists for the first three grades is provided.
So far, this is just another spelling tutor. However, xSpell lets YOU enter lists of spelling words. Up to 36 lists can be stored.
xSpell was developed to help my grandkids through their first grades. And it did !
Available at the Mac App Store. FREE !

xSpell is effective, easy to use, and FREE ! It’s a xApp !

xSight speaks a word and asks the student to select the word from a rectangular matrix. Hints are available to assist in learning a word on sight. Missed words are reviewed at the end of each lesson.
A selection of standard sight words is provided, including Dolch, Fry, and Magic 100 lists.
In addition, you can edit any of the lists or type in your own list to match your childs’s curriculum. Up to 36 lists can be entered and saved.
Available at the Mac App Store. FREE !

xSight is effective, easy to use, and FREE ! It’s a xApp !

disChord is the innovative new App that lets you play your keyboard as never before !
disChord maps a chord to a single "trigger" note. Play your trigger (or Base) note and disChord will complete the chord for you. Any chord, any size.

Please contact 99xApp with any questions you may have.
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