Hi Jevgeni,

You've probably noticed this due to the pervasiveness of material design and its paradigms in mobile UIs: material design guidelines on text fields

Google's Material Design Guidelines and Apple's Human Interface Guidelines are the "rulebooks" that mobile designers generally follow. Ultimately, it's up to the designer/developer, but staying true to platform paradigms and best practices (not reinventing the wheel) is typically best for everyone involved (more intuitive + familiar to the user, less "custom"components to design/spec/build)

More generally, I think text fields with boxes have a lot of visual weight and cramming a lot of them in a mobile UI can be overwhelming.

They're closing down after this summer: http://blog.theironyard.com/2017/07/20/message-iron-yard/

Congrats Justin & everyone else at Pixate!