DryWall calculator -- iPhone app

My iphone app for home builders.
http://itunes.apple.com/us/app/homebuilders/id389989024?mt=8

This app is intended to help Home builders to calculate values for Dry Wall, Carpet, Paint & Floor Tiles. The app allows the user to key in the different dimensions for each of the screens, calculate values, store them, associate a picture and also email them. 

The stored values can be deleted at any time. The app allows the user to configure default values for labor rates for each of the different screens. The user can also specify a tolerance value that applies to all the screens. All results will be calculated with the actual and the tolerance values. Description of the screens is below: 


COMMON FEATURE: All calculation screens have Calculate, Save, Photo, Email, Clear buttons; 
Calculate Button: Calculates the actual and the Tolerance values.; 
Save button: Saves the quote; 
Photo: Allows the user to associate a picture from your picture album with the quote.; 
Email: Allows the user to email the quote with the associated picture.; 
Clear: Clears the screen. This is also used to clear the photo selected for your quote. Ensure to tap clear after saving/emailing a quote. 

QUOTES SCREEN:  This screen lists all the saved quotes with the latest one displayed first. Tapping on a saved quote will take you to the detail. 

RESULTS: All Screens are scrollable, please scroll to the bottom to see the entire screen. Please scroll in the results area to see all the results. DRY WALL SCREEN: All units are in FEET (ft).Tap Calculate button at the top to see the results. You can either associate a picture, save it or email the quote or simply tap clear; 

PAINT SCREEN: All units are in FEET (ft). Key in the different dimensions, key in the paint coverage per Gallon in Sq Feet ; 

CARPET SCREEN: All units are in FEET (ft). 

TILES SCREEN: All units are in FEET (ft) and inches. Key in the different dimensions, You have to choose surface tile size to continue. Optionally, you may also choose border tile size. Tapping on SELECT button for the tile size displays a picker list with the different available sizes scroll through, till you see your size and tap DONE to select.