So you start thinking: "okay, cool, my team sure could use a mobile app while out on the road to access their Salesforce.com data, and the standard mobile app doesn't do what we need - so if it's so easy, lets do it."
Then you start trying to figure out how to do it and you realize, this isn't actually "easy as pie." It's actually quite involved. But, it is doable - and our development team has done it - so let me tell you what we've learned.
There are several ways to provide access through a mobile device to salesforce.com data.
Salesforce.com Mobile Device Options
1) Use the native browser on the device to login in to Salesforce.com
2) Using a Salesforce Sites page - format the output of the website to fit in a mobile browser screen size
3) Build a native application on a mobile device that can access Salesforce.com data
4) Use HTML5 and the Touch platform to deliver salesforce.com visualforce pages to a mobile device.
It is option #4 that Salesforce is advertising. And while it is WAY easier to build applications on the Touch platform than it is to build a native application on IOS or Andriod (option #3), it isn't necessarily "easy as pie".
The Touch Platform - Web Pages in an AppHere is the key thing to know about HTML5 and the touch platform: you are simply viewing a Salesforce.com visualforce page in the mobile browser on the page without the skin of the mobile browser. Even more simply: its a web page. A mobile web page. But it LOOKS LIKE an application on the device.
In Salesforce.com, visualforce makes it possible for us to write custom pages that provide custom functionality to your users. These visualforce pages can be built with display on a computer through a normal internet browser in mind, or they can be built with the intent of displaying them on a mobile device.