Features I kept waiting for in other players...that were never developed.
What it does
Auto-skips tracks that you don't really like. Introduces the concept of a 'mode' - like a scheduled playlist. E.g. on Thursday from 9 - 10am, I workout, so I want to listen to amped musical genres or x,y, and z playlists. Auto-downloads album/artist artwork, lyrics, and persists a true shuffle of all music available. All data is stored in a 3NF SQLite db.
How I built it
VS2015, Windows Phone 8.1 SDK, Windows 10 SDK over the course of several months. I own a Windows Phone running 8.1 so that was my testing platform.
Challenges I ran into
Phone 8.1 VM is not a 'true' representation of an actual phone due to continuous power, etc. Figuring out the best way to make the most code portable (in cross-platform PCL's) using SQLite, MVVMCross. Oddly enough, the biggest challenge (only partially solved) has to do with finding a clean approach to localization across all platforms (may just end up using Xamarin's approach...).
The BIGGEST headache had to with OS behavior differences between Windows Phone 8.1, Windows 10 desktop, and Windows 10 Mobile - permissions to music libraries from a background process (for example), setting the album name correctly in 8.1 for Bluetooth, and the little XAML style differences between UWP and Phone 8.1, making reusing xaml a challenge.
Accomplishments that I'm proud of
It works, and appears to work well. Took me 2 1/2 years from conception to publishing my first package, but I was just able to do so. I am the sole developer, working full time with kids, etc. so I am very proud that all my effort paid off on this first huge step of getting it published, (machine) translated into 7 languages, with (imo) pretty decent artwork for the product logo.
What I learned
Windows is still converging on a single code base, and so it is not yet truly possible to code 'once' and have it run everywhere. And that there's always a way around, through, or past a problem with enough persistence.
What's next for Attuned
Windows 10 desktop and mobile app support/release. Then Android, then Apple. Then other, better features like cloud sharing/storage, and better, more useful predictive algorithms about a user's listening habits.