Introducing StealthFly; an endless runner game for the visually impaired

App Developer

Welcome to StealthFly! StealthFly was initially created for and won the Project:Possibility USA SS12 Hackathon and has since been developed into an accessible app for iOS.

Game Play:
Suddenly, the lights dim in the plane. You can no longer see. You only have the sound of the plane whizzing past the cliffs to guide you. Enter StealthFly.

StealthFly is a single-player/multi-player endless runner game for the visually impaired which relies on sound to create obstacles. You use the phone's gyroscope to move around obstacles.
You can play the game by yourself or let the game pair you with a buddy to race against.

How does it work:
- When the sound gets higher, the obstacle is on your right.
- When the sound gets lower, the obstacle is on your left.
- Tilt your phone to avoid the obstacles!
- If you crash first, you are defeated!

App Store Link:


it takes skill, but yeah over

it takes skill, but yeah over all it's farily good, you just need to pay attention to the sounds. Having said that, I suck! Lol!

It's a bit to easy to die

I think the sound should at least be in stereo. I think it's way to easy to be killed by whatever you're running into. But i keep trying and deleting, and reinstalling.

Actually if you listen for

Actually if you listen for the pitch of the sound the lower it gets the more lft you turn. It's not easy but it works for what it is.

Take care.

Update: High Scores Now Available!

App Developer

Hey everyone! Yes, the game is supposed to be hard like similar vision-based runner games. However, your hard work will now be rewarded- we recently updated the game with high scores! That's right, your personal best will now be saved and talked back to you after finishing a round.

Why no Stereo Sound?

App Developer

Stereo is REALLY hard to play with if you aren't using headphones to play the game. It also isn't accessible for those who may have a hearing impairment in one ear (like one of our devs). Stereo actually would've been easier to implement, but pitch is more challenging and flexible in terms of platforms and users to be played with.

Stereo sound

App Developer

You could give us the choice of mono or stereo sound. That way, people with hearing impairments will not be excluded from play, but those who have enough hearing to use a stereo field can have realistic sounds. It might also be a benefit to use realistic airplane sounds as well.

That is a good idea! So, our

App Developer

That is a good idea! So, our plans for the future of StealthFly include: more realistic sounds, and background sound "ambiences" like rainstorms, thunder, etc. We can definitely put out Stereo Sound as an option to include- apparently it would be easy to implement and it could be cool to have multiple modes!

You could implement both

You could implement both stereo and pitch both. That way, you would be flying in multiple dimensions. You'd have to avoid higher and lower obstacles as well as left to right ones. My real complaint about the game is that it uses the gyroscope instead of the accelerometer, and if I've just tilted left, then need to go left again, I have to jerk it leftwards more, at least that is how it seems.
The only other distance runner type game we have currently is Echo Hear to playy, so this will be a good addition to that genre. Power-ups, coins, difficulty levels and so on will add to the game for sure. If you add enough new characteristics, you can have a whole new game and sell it for five dollars or more, and the blind will pay because there are a lot of little games, a lot of easy games, but only a few really immersive and/or challenging ones, so good luck!

I agree.

We need more games that alow poerups and other things like that. It would be quite cool to creat a running game where you're running and able to collect powerups and fight and smash things all in audio.

Violent games

App Developer

I am more-the-less in favor of the family friendly games. Some form of flight simulator like the developer had already started is good enough. Now, we need to help build an advanced concept the developer can work with. So far, we have the following:

1. Realistic airplane/ambient sounds.
2. An option for mono or stereo sound.
3. Use the phones accelerometer to improve navigation of the plane.
4. Use 3d sound instead of 2d sound because it gives a realistic impression of the world around you. For example, instead of crashing into a cliff, mountainside, trees, or other objects on the left and right sides, you can nose-dive into the ocean or ground if you do not increase altitude. While flying with an altitude to high will force the plane to stall because the oxygen level is too thin.
5. The ability to recover (or not recover) from emergencies such as a nose-dive or stall out of the plane.

Mono sound

Club AppleVis Member

Correct me if I'm wrong, but Apple already offers a mono option under General, Accessibility. Seems to me that you could just switch that on instead of having a default mono mode. I'm no expert, so I could be way off base here.

What is

What is mono audio. I mean, what is it used for? This is just an idea. I have mono audio turn off. If I turned it on, would it affect stelth fly? Would I be able to hear it on the right and Left ears, depending on where is the obstacle?

Mono audio

Club AppleVis Member

If you had mono audio turned on, you would still get audio from both sides of a set of headphones. However, from what I have been able to tell, you would only have the feedback from either the left or the right channel. Yes, it would be in both ears, but would not be a stereo mix. Hope this helps.


Thanks a lot. I tried turning on mono audio for stealth fly, and the result was the same. The sound was still herd from both sides. I think that this game needs to have its own stereo sound.

Mono vs Stereo

Mono as a prefix means one. Like, in Monopoly, the game ends when one person gets all the money. In the case of audio, mono is short for monophonic, meaning sound of one source. A moo sound means that in headphones, what each ear hears is exactly the same. In a stereo, or stereophonic sound, the right and left channels have differences that allow the listener to perceive location information.

So, with mono, you can't tell if a sound comes from the left or right, or in front of you. Stereo allows you to figure that stuff out by varying the sounds each ear hears.

Then, there's 3D audio. This uses dynamics, frequency, and time variations to further help the perception of locations such as above, behind and below. a

This is simplified, but should help clarify the discussion.

The game designers have chosen to use mono to make the game play able to as may people as possible. This sort of inclusion is to be applauded. However, those of us with stereo hearing appreciate the more immersive experience a stereo soundscape creates. The suggestion of the Apple mono setting is particularly inspired and could make this game fun for people with different abilities.

I think that

Another cool feature to add to the future update of this game, would be to have the ability to control the speed of your plane. This could be done by increasing the speed with one finger swipe up, and decreasing it with one finger swipe down. Only an idea. What do you think?

Increase plane speed

App Developer

Don't use swipe up/down to increase plane speed. I like the idea of having a single finger press and hold to increase the plane's speed because it simulates the plane's throttle mechanism. Releasing your finger will decrease the speed of the plane. The phone could act as the plane's steering wheel.


I hadn't thought of that. It is a better idea than the swipe. Besides it make the game much more realistic. Good concept by the way.