This is another iOS app that I founded, designed, marketed (building MixPlayApp.com and managing social media), and managed the contract development.
MixPlay is loved by many, and still live on the App Store averaging 30 sales/mo. with no advertising (I probably should run some ads occasionally :)
Coaching a music-based routine usually involves the annoying process of repeatedly "scrubbing" to find the right part of the routine tp play while your team is practicing that part. It's also tedious to get your routine music (usually an mp3 emailed to you) stored locally into your phone's music app.
I'm not an iOS developer, so I hired a contract developer. My small budget limited my development hours, so I had to be careful to get it as right as possible the first time.
As the solopreneur, I did everything but build it:
I hired a freelancer from UpWork to build the app. He was from China, and his English was not too good, so we had to rely on written communication. It took quite awhile to convey the concept of running parts of music at cheer/dance pracitce! However, he wrote good code — Apple's stats show there are usually zero crashes over the thousands of sessions per month.
Since I was coaching the KU Cheerleading team in the evenings, I was the target market so I already understood the needs well. Most of the work was in iterating to achieve:
Many coaches love the time-saving app and use it every day at practice. Sales of the $3 app are modest but steady even without advertising.
I also translated MixPlay into multiple languages and published it to those countries' App Stores: Deutsche, English, Español, Français, Italiano, Português, Русский, 简体中文, 中國傳統的, 日本語, 한국어.