Prototyping Accessible Apps with ProtoPie

Gary Bartos
3 min readOct 19, 2020

In his book The Human Interface Jef Raskin wrote, “As far as the customer is concerned, the interface is the product.” I’ve repeated this phrase numerous times in conversations and presentations since I first read Raskin’s book, and the quote was often on my mind when I designed interfaces for industrial automation systems.

When you emphasize usability, you’ll find yourself drawn to prototyping interactions early in product development — preferably before you unleash programmers to write algorithms, create databases, and create other low-level code. There are dozens of tools to create prototypes of varying complexity, from low fidelity wireframes that look like napkin sketches to high fidelity prototypes that run on mobile device and emulate functional apps.

I‘m developing a mobile app for the blind, the DeafBlind, and those with low vision. Virtually all prototyping software is limited to graphical design, whereas I need access the phone’s hardware to test audio and haptic interactions.

After searching, I found only three prototyping tools that provide access to a mobile phone’s hardware: Framer Desktop, Origami Studio, and ProtoPie.

To learn a bit about each tool, visit the following page:

Scroll until you find the Sensors column, and then click the Sensors column header to see Framer, Origami, and ProtoPie as the only packages offering sensor access. In my earlier googling I stumbled onto a fourth package, Antetype, although they appeared to be moving from desktop software to web-based software, and for me the ability to work offline is critical.

After looking at reviews, watching videos, and visiting the websites, I settled on ProtoPie.

For prototyping the emphasis is speed. With ProtoPie I was able to download the free trial, stumble my way through one of their samples, create my own prototype, and have a colleague test it within half a day. More recently, I’ve been able to make changes to prototypes during Zoom calls and have a colleague test the new version while we’re still on the call. I’ve been averaging about one prototype per day.

For the prototypes I’ve tested use of tap, double tab, drag, and other touch interactions; phone rotations (“tilt” in ProtoPie parlance; text to speech; and audio playback.

My original plan was to use ProtoPie for the 30-day trial period, then spend at least a few days each with Origami and Framer Desktop, but ProtoPie’s no-code approach to creating prototypes proved useful enough that I started a monthly subscription.

Framer Desktop and Origami Studio seem to require some level of coding in Quartz Composer. Though that could make it possible to create even higher fidelity prototypes, I’m already busy learning the Swift programming language for iOS development. If I want to prototype an image processing feature or some involved interaction with VoiceOver on the iPhone, I might as well just create a proper app at that point.

I won’t delve into the specifics of design for accessibility today. My main point today is that if you’re involved in creating accessible mobile apps— whether you’re a programmer or not — you should give ProtoPie a try. Within the 30-day trial you’ll certainly have enough time to determine whether its ease of use, features, and price suit your needs.



Gary Bartos

Founder of Echobatix, engineer, inventor of assistive technology for people with disabilities. Keen on accessible gaming.