The Processing.js is available for Linux, Mac OS X, and Windows and come with the last version 3.3.7 (13 March 2018).
Today I tested processing.js for android. They say us about this issue:
Use Processing for Android to create Android apps with ease, including live wallpapers, watch faces, and VR apps. You can run your Processing sketches on Android devices (phones, tablets, watches) with little or no changes in the code, and without worrying about installing SDK files or editing layout files. Processing for Android also lets you accessing the Android API to read sensor data, and exporting your sketch as a signed package ready to upload to the Google Play Store.
To use processing.js for android you need to follow this links:
They tell us about new android processing :
The version 4.0 brings several improvements to the Android mode, incuding new functionality for creating live wallpapers, watch faces, and VR apps.