How We Built the Shredder

It Had to Feel Real

When we started building UNHEAVY, the first destruction mode was the shredder. And the first version was terrible. It looked like a shredder. It animated like a shredder. Paper went in the top, strips came out the bottom. Technically correct. Emotionally empty.

The problem was obvious the first time we tested it: watching a flat animation of paper getting cut doesn't make you feel anything. It's like watching a video of someone else popping bubble wrap. You can see the thing happening, but your body doesn't register it. There's no satisfaction.

So we scrapped it and started over with a different question. Not "how do we animate a shredder?" but "how do we make someone's phone feel like it's tearing something apart?"

The Sound Design

Sound is responsible for more of the "feel" than most people realize. Close your eyes and listen to a shredder, and you can almost feel the paper being cut. That's what we needed to recreate.

We layered multiple audio channels that play simultaneously during destruction:

• A base layer of tearing paper, recorded at different speeds and distances. We recorded real paper being torn, cut with scissors, and fed through an actual office shredder, then mixed the best elements.
• A mechanical hum that ramps up as the paper feeds in. This gives the sense of a machine with weight and power, not just a visual effect.
• Micro-variations in pitch and timing so it never sounds exactly the same twice. Repetitive sounds become invisible to your brain after a few uses. Variations keep it feeling fresh.
• A subtle "thunk" when the paper first makes contact with the blades. This is the moment of commitment. The sound confirms: this is happening.

The sound needed to be satisfying without being aggressive. We went through dozens of iterations to find the right balance. Too sharp and it felt violent. Too soft and it felt like a toy. The final version lands somewhere between an office shredder and an ASMR video. Crisp, clean, and strangely pleasant.

The Haptics

iOS gives developers access to a sophisticated haptic engine, and we pushed it hard. Every destruction mode uses custom haptic patterns that are synchronized to the visual and audio experience.

The shredder uses a rapid, rhythmic vibration pattern that maps to the visual speed of the paper being cut. As the paper accelerates into the blades, the haptic frequency increases. When a strip separates, there's a tiny burst. When the last strip falls, there's a final punctuation... a single, clean tap that says "done."

We tested dozens of haptic combinations with real users. The feedback was surprisingly consistent: too soft and you don't feel it, so the destruction feels like it's happening on the screen but not to you. Too strong and it feels like a notification buzz, which triggers the exact kind of stress response we're trying to relieve. The right pattern sits in a narrow band between those two extremes.

The goal was to make your hand feel like it's holding something that's being torn apart. Not your phone vibrating. The thing in your hand being destroyed.

The Visual Physics

Early versions of the shredder had paper strips falling straight down in uniform rows. It looked like a screensaver, not a machine. Real shredders produce chaotic output. Strips curl, twist, pile up unevenly, and drift as they fall. We needed to capture that chaos.

Each paper strip in UNHEAVY is an individual physics object with its own properties:

• A slight random rotation as it separates from the page. No two strips detach at exactly the same angle.
• Variable fall speed based on strip width and the randomized "weight" of each piece.
• A gentle side-to-side drift as it descends, simulating air resistance on a light piece of paper.
• Subtle spin on the vertical axis, so strips appear to tumble rather than glide.
• Opacity fade and scale reduction as strips pile up at the bottom, creating a sense of depth.

We also added text rendering to the strips. You can see fragments of your actual words on the falling pieces. This is a small detail, but it's critical for the psychological effect. You're not just watching generic paper get shredded. You're watching your thoughts get shredded. Your words, broken into pieces, tumbling into nothing.

These are small details that most people won't consciously notice. But their absence is immediately noticeable. The difference between "this looks like a shredder animation" and "I just shredded something" lives in those details.

The Moment of Contact

The single most important moment in the shredder experience is when the paper first touches the blades. We spent more time on this one transition than on anything else.

When you drag your writing toward the shredder, there's a moment of resistance. A brief pause where the machine "grabs" the paper. The haptics shift. The sound changes from ambient hum to active cutting. The paper begins to move on its own, pulled into the machine.

This is the point of no return, and it needs to feel like one. You committed. The machine took over. Your words are now being destroyed, and you can't get them back. That irreversibility is central to the entire experience. If you could undo it, the relief wouldn't work.

Why Any of This Matters

UNHEAVY is an app about feeling lighter. That sounds simple, but "feeling" is the operative word. If the destruction doesn't feel real, the relief doesn't feel real. If the shredder looks like a shredder but feels like a screen, you're just watching an animation. You're not releasing anything.

Every pixel, every sound, every vibration pattern is designed to make your nervous system believe something just happened. Not something on a screen. Something to you. Something to the thought that was weighing you down.

That's the bar we hold every feature to. Not "does it look good?" but "does it feel real?"

We don't simulate destruction. We create the experience of it.

Open UNHEAVY and try the shredder yourself. Write something that's been sitting heavy. Feed it to the machine. Feel it go.