Simple, Visual KPI is built by a software company that does nothing but worry about making the application rock-solid, reliable and most importantly compatible. After years building and releasing enterprise applications at companies like Microsoft and OSIsoft, we know that standards are rarely standard and that once someone deviates from it (e.g. company standardizes on Blackberry, but some exec decides they need an iPad or the latest model with the new OS) the work increases exponentially.
It tooks years for us (who are experts in this stuff) to design a server that was smart enough to recoginize all of your devices and auto-generate compatible screens and deliver them securely. We worry about Blackberry updates, iPhone vs. iPad, Android screen sizes, horizontal vs. vertical aspect ratios, keyboards, web browsers on the PC and Mac and more so you don't have to.
Applications like this can be built, but this often takes many months (or years) and significant resources beyond the cost of a Visual KPI deployment. Even if you want to build your own application, we suggest you try Visual KPI for 30 days (for free) and see if it meets your mobile monitoring needs.