As an Android dveloper I ask to a server for data like the one on the left and I make them more suitable to humans
As a backend developer I use technologies like Ruby On Rails(5+ years) or Node.js (3+ year).
With those language I take data from a databse like Mysql or Postgresql, maybe do some processing and spit out a "view" of this data.
Sometimes traditional database are not the best choice for certain task, so I can use things like ElasticSearch, Redis, CouchDB or MongoDB
As an android developer I use Java and the Andorid API in order to create application.
I think there are moslty two concerns where we are talking about mobile code.
The first one is that is so fast forward moving that not doing a clean code is
leads quickly to a technical debt because the development cycle is usually shorter than the backend.
The problem is that you have a limited device that have limited resources and most of the time good programming means using more resources.
The second one is that the usage of a phone is actally much different than the website usage, a smartphone app is used for short burst of time (seconds/minutes) while you can use a website for long period of time (minutes/hours).