We are using Bungie’s Destiny 2 API, which really gives a ton of information about what is going on in game. I honestly think its one of the best ways a company can support and build a community, and Bungie has really knocked it out of the park.
We built the app using Google’s Flutter and Dart. We have been really impressed with Flutter, both development time, speed and performance, and especially its ability to compile across platforms (we target iOS iPhone and iPad, and Android phones). If you are building a custom UI and want to target multiple platforms, I would really give Flutter a look (I am really excited about some of the work the team is doing to bring Flutter apps to the desktop).
Note, we are using Redux for Flutter for state management. It has a lot of boilerplate code, but really eased development, and in particular, made it easy for Grant and I to work together, and focus on our areas of code (Grant UI / experience, me on the middleware and backend).
Shout out to Grant for all of the app and website design also. The community has called out how great the design is, and its really a testament to the impact and importance of the design and user experience.
We are having a lot of fun working on the app, and plan to keep building on it. You can find more information, including how to download at redrix.io.