knock

Knock is an app for friends to swap silent video messages.

Inspiration: the doorbell camera is social

The thematic inspiration came from the doorbell or apartment building cameras that turn video on when someone buzzes up. It’s a fun little moment to see friends smiling, waving, making funny faces or just looking totally oblivious, staring off into space at an unflattering angle :) The Ring doorbell cameras at homes are fun to use for another purpose too, leaving little messages for family members or friends that might watch the camera feed later on.

Theory: why 'silent video' is compelling

We were inspired by the idea of sensory constraints unlocking new types of experiences, and we thought a lot about the unassuming but compelling elements of ‘silent video.'

Lower friction to create and consume than traditional video.

When you don’t have to think about what to say or the sounds in your environment, it lowers the barrier to creating video (TikTok encouraging to overlay sounds actually helps with this). It’s increasingly common to watch short-form videos on mute, whether you’re scrolling YouTube, Twitter, or even on TikTok (almost every video has captions). It’s practical because people aren’t always in private spaces or using headphones. Silence is also a nice change from noise we’ve gotten so used to consuming.

More expressive than photos and more personal than GIFs.

Static photos are good for capturing poses and aesthetic scenes but they’re not as expressive or immersive as videos. Live photos on iPhone have a similar vibe but aren’t consumable or immersive enough. GIFs are similar in the sensory format, but they’re memes more than moments. Putting the analysis aside, a good silent video makes you pay attention more closely, kind of like reading a book instead of listening to the audiobook.

Design & Product: incorporating the theme

We built the first version over a weekend, and had to wait a day for TestFlight approval to ship it. We started with a few simple components: onboarding, a central feed, a camera, and a friends selector. 

A few of the initial design and UX choices centered around this question: How much of the thematic inspiration should we bring into the UX? We had wacky ideas to make the app extremely thematic, but decided to go light first:

  • Shape of the video containers: we created a pill-shaped container that mimicked the view through a doorbell camera or doorhole. We thought of adding a subtle fisheye effect to further the effect, but thought this could be optional in a v2.


  • Placement & functionality of the camera: we chose to put the video camera in a modal to simulate the choice to knock on the door, ring up, etc. The best alternative was to do the now standard ‘open to camera’ that Snap and others do (might reduce the friction and reinforce the core action). We also chose to only allow selfie-mode (no flip camera option).


  • Network graph & curation: with any friends-based social product, you have the same graph questions. Should the core action be 1:1, 1:many, or group-based. The thematic inspiration would suggest 1:1, but we also thought about who you'd be comfortable sharing with and who would like seeing the videos, and settled on 1:many (share with all your friends).

Evolution: what we learned

There's a lot we learned through using the product ourselves and through feedback from early users. To skim the surface, a couple major things:

  • People like seeing their friends' faces. This sounds obvious, but lots of people told us that on most other photo or content-sharing networks, they no longer get to see friends' faces. Instead, they see their friends' surroundings or something more staged even. Even though some users asked for a flip camera option, this was the counterargument.

  • People want to choose who to send a knock to. The 1:many sharing default meant that 1) people wanted to be more careful who they added as friends 2) people felt hesitant to send some knocks that they otherwise would have if they had added less friends (or could choose who to send to).

That's a wrap on the peek behind the curtain for Knock v1, but stay tuned for more on what's next! 🧡

Home