An immersive app doesn’t just look or feel great: It has to sound amazing, too. We asked several of our Apple Design Award-nominated developers to share their philosophy around making music, audio design, and sound. (And occasionally frogs.)

Poolsuite FM: Hot fun in the summertime

Let’s just come right out and say it: Poolsuite FM is the perfect summer mood. This bitmapped, genre-hopping, beach party jukebox immerses you in 90s design nostalgia while maintaining a great technical experience behind the scenes. And it was invented not by a reggae artist or an Ibiza DJ but an affable Scot named Marty Bell who, prior to developing his poolside player, had no musical training, no tech background, no money to hire help, and — this part is key — definitely no pool.

What he did have was the keen idea to synthesize that summer feeling and his well-honed ability to curate music that sounds like sunshine. “I have a pool in my head,” Bell says. “I imagine 10 people hanging out. They’re all way cooler than me. And I think, ‘OK, would I play this song in that scenario?’” he laughs. “The stakes are really high.”

Poolsuite FM (known until very recently as Poolside FM) was conceived during the uncommonly dismal Scottish winter of 2014. “It was a very gray time,” Bell says from his home in the Scottish highlands (though he’d recently returned from a “seven-month Covid escape” to the Dominican Republic). “It was cold and spitting rain all the time. Listening to this music just boosted the serotonin in my brain.”

Bell wanted to spread sunshine to others, but as a longtime party planner, he also knew that a simple playlist app would be a hard sell. “Everybody thinks they have the best playlist,” he laughs. “I thought, ‘Why don’t I take this summer thing that makes me feel happy and pair with something else that makes me feel happy: cheesy ‘80s beach movies on VHS?”

Properly drenched in technological nostalgia and positive vibrations, Poolsuite FM made an instant splash. Its look mirrored the Mac you had in 1994; its playlists were curated by Bell and often drawn from under-the-radar artists on Soundcloud and YouTube; and its sound was decidedly all over the map. “There’s disco, indie rock, and electronic music,” he says, “but I feel like it’s all in the same family.”

Today, Poolsuite FM has a deep well of stations like Indie Summer, Hangover Club, Tokyo Disco, and Friday Nite Heat. Its primary channel has 600 tracks; Bell adds a dozen or so every week through his own curation and submissions he gets on social media. “I’d far prefer Poolsuite to be bursting with artists people had never heard of,” he says.

And there’s one last surprise: Poolsuite FM has never monetized. Bell relies on volunteer help; to start bringing in money, he’s launched a sunscreen line. “I don’t ever want to monetize Poolsuite,” he says. “I don’t want to track metrics and KPIs and all that. It would kill the vibe.” And summer is nothing if not a vibe.

If Found: Intergalactic planetary

If Found isn’t like any other game. Or app. (Frankly we’re still working out what to call it.) It’s an immersive sci-fi coming-of-age story centered around a journal kept by its protagonist, a young transgender woman named Kasio. To (greatly) simplify the experience, you progress through the story by erasing each scene with your finger, gradually unifying the (seemingly very disparate) narrative strands as you scrub. All the while, you’re gently guided along by audio designers/composers Eli Rainsberry and Matt Hopkins.

“I wanted to get the feeling that you could open this journal and hear everything in your head, like you were daydreaming,” says Rainsberry.

A gaming industry vet whose work can also be heard on Bird Alone, A Monster’s Expedition, and Wilmot’s Warehouse, Rainsberry strongly connected with If Found’s subtler, more emotional “notebook” sequences. “That’s where I could work more intimately with the erasing system,” they say. “The cliffside scenes start with softer winds; as Kasio moves along in the story, things gets colder and thinner.” Rainsberry felt the arc of the notebook scenes called for an analog approach, one heavy on acoustic guitar, mandolin, and harmonica. “I wanted to replicate memories fading away,” they say.

Hopkins, who records under the moniker 2 Mello, composed the more dramatic scenes — including a cinematic and celestial opening sequence, which drops you into deep space and gradually compels you to erase entire planets (and then something even bigger).

To do so, he drew on 90s electronica, leaning in equally to the frenetic roar of The Prodigy and the more analog approach of Aphex Twin. “It’s pretty rare that you get asked to do anything that sounds like pop music for a video game,” he says. “It’s usually more about emotions and mood. But that was my inspiration this time. I even managed to sneak a little breakbeat in there.”

If this all sounds a little mysterious, that’s the idea: If Found’s storylines weave around each other like ribbons, coalescing in an ending that also unifies the pair’s work. “I sampled some of Eli’s stuff there, where the notebook is constantly switching places with real life,” says Hopkins. Rainsberry has their own notes about it: “I provide quiet moments to give people space to process what’s going on, and then Matt comes in with incredible climax music. It’s a really nice balance.”

Pok Pok Playroom: The kids are alright

While crafting the inventive children’s sandbox Pok Pok Playroom, Esther Huybreghts and Mathijs Demaeght made a solemn vow: “We wanted something parents wouldn’t have to mute in a restaurant,” Huybreghts laughs. “We didn’t want media and jingles and jangles that get stuck in your head. We wanted a quieter experience.”

To the delight of grown-up diners everywhere, they got it: Pok Pok Playroom is a tasteful feast for little senses. There are hand-drawn switches to flip, gears to grind, blobs to plop together, and bells to ring. But they’re all done with a judicious aural balance that activates young minds while also leaving space for kids to fill in details with their own imaginations. That’s all thanks of sound designer Matt Miller, who took initial audio ideas from Demaeght and jumped into the project with his entire … well, mouth.

“I started by making little sounds: ‘choo choo, quack quack,’” says the Toronto-based Miller. “It was all very embarrassing.”

It also worked. Miller went on to record every sound in the Playroom: all the sloshing mops, sizzling grills, and wordless dialogue were entirely provided by he and his wife, Cathy. “The idea was to create calming sounds,” says Miller, “something that could be heard a number of times without becoming fatiguing.” (Here we’ll give parents and caregivers a moment to nod appreciatively.)

Initially, Miller and Demaeght wanted to use a small number of real-world objects, but they quickly realized that the app’s 500 animations required a broader arsenal of sounds — so Miller went on a hunt. “I got wooden blocks, pots from the kitchen, stuff I bought at a local thrift store,” Miller says, pointing to a boxes of “Foley objects” in the background of his home studio. “I’d just walk into a music store and start pinging on things.”

His biggest challenge came in the app’s “musical blobs” section — an abstract playspace of movable shapes. “A musical blob is a completely new idea,” Miller says. “A lot has to come together for that to work.” For instance: The color blue is always a C, while circles (the simplest of shapes) are represented by a single sine wave (the simplest of sounds). “There needs to be a consistency,” says Miller.

But like his target audience, Miller also found room for a little play: One of his favorite effects involves a dung beetle that raises its back legs and rolls the dung away. “That rolling sound is just me rolling over the edges of a soup can,” he laughs. “When we can be literal, we’re literal. But it’s fun to throw curveballs, too.”

Loona: Night time is the right time

One workday morning last year, Loona founder Andrew Yanchurevich texted team sound director Ivan Senkevich to ask why he wasn’t in the office yet. Luckily, Senkevich had very good answer: He was out looking for frogs.

More specifically, Senkevich was looking for the sounds of frogs — recordings he could integrate into his team’s sleep app. “My region has a great natural sound,” says Senkevich of the area around his hometown of Minsk, Belarus. “I came into my village often to record.”

He had plenty of reason to do so. Part bedtime story, part interactive activity, and all gorgeous, Loona is an app that winds you down with “sleepscapes” — blends of sound, story, and narration designed to soothe your mind at bedtime. (Think of them as meditative interactive storybooks.)

To create the appropriately somnolent aural environment, Senkevich often hit the road, traveling around town in search of not just amphibian friends but breezy forests, babbling rivers, and the buzz of insect life. “Some of the sleepscapes are more cartoonish and some more realistic. But we always try to show the natural-ness of the sound.” (Some sounds, he notes, did come from libraries. “You can’t record the sea in Minsk,” Senkevich says with a laugh.)

Sound is a crucial ingredient in Loona’s restful recipe of art, storytelling, graphics, music, and sleep science. To hear Yanchurevich tell it, that magical mix is driven by Senkevich’s history in both graphics and audio design. “Ivan came to us with experience in both,” says Yanchurevich. “He feels that connection between two worlds. That’s his superpower.”

The resulting app is designed, as Yanchurevich says, to “recreate this safe bubble from your childhood.” In the introductory sleepscape “The Dragon’s Shrine,” you’ll explore a beautifully-rendered marble pagoda while an appropriately-mellifluous voice guides you through calming, repetitive tasks like lighting lanterns and coloring in architectural details. As you progress through sleepscapes, you’ll lose yourself in a fairytale kingdom, explore a dark forest (which sounds a lot like Minsk), or simply cozy up to a crackling fire. Music comes from a team of sound freelance musicians that stretches from Brazil to Asia to the United States and incorporates the culture of each. But the final product is a single design. “We try to present the graphics and audio as one thought,” Senkevich says.

NaadSadhana: Extraordinary machine

NaadSadhana is the sort of astonishing, future-world app that could only be created by someone with an extremely specialized, almost-impossible skill set.

Sandeep Ranade was that someone.

With the help of AI, the app listens as you improvise a vocal line, then generates a backing track to match — all in real time. NaadSadhana (a mix of the Sanskrit words for “essence of sound” and “systemic practice”) has neither stock riffs nor repeating loops; its 10 instruments, including virtual tanpura, tabla, and harmonium, are as spontaneous as your vocals. And with features like visual biofeedback, it’s a powerful tool for blind or hard-of-hearing people.

Ranade was perfectly positioned to create such a project. The Pune-based developer began singing at 4; by the 11th grade, he was an excellent singer who also exhibited skill in software engineering. “I needed to decide whether to go into either software or music,” Ranade says, “and I decided I wanted to do both professionally.”

He pursued that dual track for years (as well as a few others: Ranade has a masters from Johns Hopkins, two decades of tech-world experience, and a thriving career as a Hindustani classical vocalist). All the while, he kept teaching, but inefficiencies in the process nagged at him. Training for Indian classical singing is an intense and demanding process; in the “ancient system,” Ranade says, students would live with their teachers and practice for 10 hours a day, every day. Today, that timing isn’t possible, but the work remains the same.

“If you don’t have frequent course correction, your neural pathways won’t converge to where they need to be,” he says. “I needed something that would tell students, ‘You’re just a little bit flat here, a little sharp there.’” Unable to find a solution — and despite having no background in Swift, Xcode, AI, graphic design, or designing mobile apps — he set out to build it himself.

From there, Ranade began tweaking. He added an AI to detect what was singing and what was not, but felt room for more. “I wanted accompaniment,” he says. “Instruments like a swarmandal, which has 40 strings, are hard to tune and travel with. I thought, ‘What if something could play close to as well as I can, stay in tune, and fit on my phone?’”

He gave the app a test run by recording “Na Corona Karo,” a song about taking precautions against COVID-19 that became a viral hit shared by A.R. Rahman and others. But Ranade was most moved by the reaction he got from the leaders in his field. “Musical geniuses like my late guru thought it was real human accompaniment,” he says. “They were astonished it was software.”

Today, NadSaadhana features automatic harmonies on violin, piano, and harmonium as well as percussion instruments like shakers and ankle bells. Its AI is trained not to adjust to the complexities of each instrument, but to the mix of the orchestra and the mood of the singer. “It’s not as simple as ‘This is the note he’s singing, so here are the chords,’” Ranade says. “There has to be context: Is he singing slower or faster? Does he sound sadder or more upbeat? That changes the chords you hear, from all the thousands possible.” Some bands rage against machines; Ranade’s future is working more closely with them.