The sonar pen’s a really inexpensive way to get pressure sensitivity for IOS, Android, and ChromeOS. It just utilizes the headphone jack, or a adapter, but the app needs to support it
A couple of things to note:
the pen needs to be calibrated per device. This is done via a separate app.
It can be really sensitive depending on how the pressure curve is set. In my experience with it in Ibis Paint, having a linear pressure curve works best.
it doesn’t. They have their own SDK, as I think stylus’ like Wacom use some radiofrequency. This uses, in a sense, sound, hence the name. They in fact, reached out to you guys almost 2 years ago to add support for it through the forums: Supporting a super affordable pressure sensitive stylus in the Android version
And if you had read that topic to the end, as well as understood its content and statement, then it should be clear to you why this stylus is not supported, respectively cannot be supported.