Mixer transposition
Change the key. Keep the tracks together
Transpose a song in the audio mixer and adjust individual parts for rehearsal.
Watch in the help centerWORSHIPONLINE / MOBILE + AUDIO ENGINEERING
A rehearsal app
A custom audio engine
A launch we owned
From React Native screens to native C audio processing, we built an iOS and Android app and helped the client get it into musicians' hands
ApplicationReact Native · iOS + Android
AudioCustom native C library
OwnershipBuild · Publish · Support
THE PRODUCT
Bring the rehearsal experience to a musician's phone
WorshipOnline wanted a mobile application that let musicians learn their parts wherever they rehearsed. We developed the app for iOS and Android with React Native, adapted the existing backend, and brought the product through publication on both stores.
The demanding part was the audio. The mixer needed to combine multiple streams and give musicians control over each part while keeping playback synchronized. The proprietary audio solutions we evaluated came with licensing costs that were too high for the project.
THE ENGINEERING CHALLENGE
Build the audio capability the product needed
We could not find a ready-made React Native library that met the project's synchronization and cost requirements. We built the required audio library from scratch in C at a much lower cost than the proprietary licensing options we had considered.
- 01
Keep the tracks synchronized
Mix several audio streams while supporting per-track volume, stereo panning, mute, solo, and seeking. Changes to playback must not let one part drift away from the others.
- 02
Learn the signal-processing theory
AI-generated prototypes repeatedly produced tracks that fell out of sync. We studied the audio signal-processing theory, worked through the timing problem, and implemented the processing ourselves in C.
- 03
Bring the native engine into React Native
We connected the custom library to the shared React Native application through a native module, making the audio functionality available on both iOS and Android.
One reusable native audio library
The team gained the functionality it needed for both platforms without adopting the expensive proprietary audio SDKs we evaluated.
SEE THE PRODUCT WORK
The features, in the client's own walkthroughs
These public WorshipOnline help videos demonstrate the current iPhone and iPad experience
Tabs transposition
Practice the tabs in your key
Move the guitar or bass tabs into the key you need to play.
Watch in the help center
Tutorial video looping
Repeat the part you need to learn
Loop a section of a tutorial so musicians can work through a difficult passage.
Watch in the help centerDELIVERY + OWNERSHIP
Get it live. Help the team keep it moving
Our responsibility included supporting the client's team through publication on the Apple App Store and Google Play. We stayed involved as the product moved from implementation into release and ongoing development.
Build across both platforms
Connect the shared React Native application, native audio functionality, and existing backend.
Support store publication
Help the client navigate the iOS and Android release process and bring the app to both stores.
Keep project ownership
Support the client's team along the way, resolve technical challenges, and continue helping the application evolve.
A PRODUCT PEOPLE USE
Published on both stores. Rated by musicians
React NativeShared app for iOS and Android
C audio engineCustom processing with synchronized tracks
Both storesPublication and client-team support
FROM TECHNICAL CHALLENGE TO LIVE PRODUCT
Need a team that owns the difficult part?
We combine application development with the engineering needed to make the product work, then help your team through release and ongoing improvements.
Discuss your application