Google Spreadsheet unable to deploy web app script -- - google-apps-script

Question

I've been trying to deploy this web app bound to my shared spreadsheet. Basically it's a script that locks a cell after it's been edited. It is working just fine when I access it, however when I switch to another user and try, it doesn't function. You would think it would be a sharing permission setting, but I've changed everything to public and still no luck. Can you someone please help?
Here is the script:
function doGet(e) {
var sheet = SpreadsheetApp.openById('1234567891011');
}
function onEdit(){
var masterSheetName = "PlaceYourSquare" // sheet where the cells are protected from updates
var helperSheetName = "Helper" // sheet where the values are copied for later checking
var firstDataRow = 1; // only take into account edits on or below this row
var firstDataColumn = 1; // only take into account edits on or to the right of this column
var ss = SpreadsheetApp.getActiveSpreadsheet();
var masterSheet = ss.getActiveSheet();
if (masterSheet.getName() != masterSheetName) return;
var masterCell = masterSheet.getActiveCell();
if (masterCell.getRow() < firstDataRow || masterCell.getColumn() < firstDataColumn) return;
var helperSheet = ss.getSheetByName(helperSheetName);
var helperCell = helperSheet.getRange(masterCell.getA1Notation());
var newValue = masterCell.getValue();
var oldValue = helperCell.getValue();
if (oldValue == "") {
helperCell.setValue(newValue);
} else {
masterCell.setValue(oldValue);
}
}