I am busy doing a little proof-of-concept solution to produce a mobile app using a BSP application as a container. In concept, this sounds easy, but there are always snags that slow down the development process, particularly trying to test AJAX calls to a remote server from a locally hosted app.
A while back I had the opportunity to investigate SAPUI5 as an option for user interfaces on our current project. Here is a quick little getting started guide that I wrote back then, partly for my own benefit in case I ever need to get started on it again.
Sometimes source code modules get very big. You can argue that this should never be the case, if you modularize your code properly, but the fact is that they do. And when they do, they sometimes become difficult to read.