Build with Mobile-First Focus
Build apps with a mobile-first focus (not just shrinking backend screens onto a mobile device).
Business mobile applications are quite often built as an extension of a backend desktop system or website. The focus of such applications is not the end user but rather the backend system itself, so if it's replicated directly, it usually results in a shrunk down backend system on the screen of a mobile device.
Many people fail to realize that the user interaction on a mobile device is completely different from the user interaction on a laptop or PC. Desktop applications utilize a mouse to click on small buttons and controls. This is much more difficult using fingers or even a stylus on a mobile device.
Every mobile application should be designed with the user interaction in mind. Controls have to be made bigger while colors and fonts need to be readable on small devices both indoors and outdoors.