When the Apple Pencil was released, I was briefly outraged by the fact that it wasn’t supported by older iPads, then sucked it up and bought an iPad Pro. Hong Kong-based company Greenbulb is setting out to minimize this dilemma by crowdfunding SonarPen, a $30 stylus that senses pressure via the headphone jack, so it works with any iPad released after 2011.

The SonarPen works by turning pressure information into sound waves sent to the iPad through the audio cable, which the iPad then interprets back into digital information. Because it uses an analog signal, Greenbulb claims it can deliver a wider range of pressure sensitivity than a standard Bluetooth stylus. And since there’s no Bluetooth to fiddle around with or batteries to charge, the SonarPen just works right when you plug it into the 3.5mm audio jack or through a Lightning adapter.

I got to try out a 3D-printed prototype and found that it worked pretty seamlessly on all the iPads I tried it with: the fourth-gen iPad, the 9.7-inch iPad Pro, and the 12.9-inch iPad Pro. Just for kicks, I even tried it out on my iPhone X using the dongle, and it worked perfectly. The cable does get in the way sometimes, but that’s the price you have to pay for it to work!

Developers will have to individually add support for the SonarPen to their apps, which could become a big limitation. The stylus only supports pressure sensitivity and palm rejection on two apps so far — ZenBrush 2 and GoodNotes, though in fairness it’s an unreleased product — but it still works as a “dumb stylus” sans these features on any other app. The Kickstarter has already surpassed its $25,573 goal in seven days, and it’s expected to ship in June.

For comparison, the closest thing in the market in that price range is the Adonit Jot Pro, which is also around $30. It’s wireless, but it doesn’t support palm rejection or pressure sensitivity. You’d usually have to go up to around $75 for a stylus with pressure sensitivity support (like the Wacom Intuos Creative Stylus or Adonit Pixel), though it’d have the benefit of being wireless.

For what it is, the SonarPen is cheap enough that it would be great for kids or to get some more use out of any old iPads. If SonarPen could eventually get pressure sensitivity working for art apps like Procreate, it would be a formidable alternative to the Apple Pencil. It’s even got a button on the side you can remap, which is a one-up over the Pencil.