Basically, you upload your data document to the Roambi server, which formats it according to one of its templates, and then sends it to your iPhone all nice and pretty. There are some small things that need working on, though. Large Excel spread sheets upload fine, but there is no quick find feature, meaning you have to scroll like crazy to get to the end. If you use the Go To feature, it does not go directly to your goal, bur rather scrolls automatically, taking just as much time as you would have to do it yourself. So for large data files, it's impractical. I would love to use it for an important spreadsheet I have with 1000+ entries and multiple columns. The columns work out fine, but the inability to go quickly to the end, and then back, makes it hard to use. (Also, if you have confidential data, you have to trust their privacy policy since you're basically running your data through their server.)