Metadata, outputs and calculates in Build

We are excited to announce that ODK Build now has support for metadata
prompts, outputs in captions, and calculates on prompts! As explained
below, these features enable users to build higher quality forms.

Metadata
Metadata prompts are hidden prompts in the ODK form that the data
collector does not see. In Build, there is now support for metadata
like timestamps for when the form was started and finished as well as
metadata that uniquely identifies the device. These new prompt types
are at the bottom of screen in Build and can be treated like any other
prompt type (drag and drop as needed). Build also now automatically
includes a special kind of metadata called instanceID. instanceIDs
uniquely identify the completed form and help ensure that no duplicate
forms end up in the final dataset.

Outputs
Build now supports the ${/data/dataName} output syntax for referring
to previous answers in captions and hints. For example, users can now
have a caption that reads:
Your device ID is ${/data/deviceID}. Your first name is ${/data/firstName}.

When a data collector sees this caption on the device, it be filled in
with the answers previously given. In this case, if a form designer
had a metadata prompt called "deviceID" and a text prompt called
"firstName" that was previously answered, the caption would read:
Your device ID is 12:34:56:78:90. Your first name is Yaw.

Calculates
Calculates are an advanced technique for running a calculation using a
prompt's answers. Because they are complex to use, they are found
under the advanced section of Build's prompt properties. Find out more
about how to use calculates in the form design guide.

Metadata, outputs, and calculates are available because CartONG hired
the ODK consultants at Nafundi to work with ODK Build creator Clint
Tseng on these features. Thanks to CartONG for funding these
contributions to the community!

You can try these changes today at http://build.opendatakit.org. If
you need a sample form or want too see screenshots, go to
http://opendatakit.org/2013/01/metadata-outputs-and-calculates-in-odk-build