singleton model for #tialloy InApp purchases for iOS using StoreKit module

purchase.js

var Storekit = require('ti.storekit');

Storekit.receiptVerificationSandbox = true;
Storekit.receiptVerificationSharedSecret = "********************************";

var verifyingReceipts = false;

exports.definition = {
        config: {
		"columns": {
			"title":"TEXT",
			"description":"TEXT",
			"productid":"TEXT",
			"appleid":"TEXT",
			"purchased":"integer"
		},
		"adapter": {
			"type": "sql",
			"collection_name": "purchases"
		}
	},
	"defaults" : {
		"title":"",
		"description":"",
		"productid":"",
		"appleid":"",
		"purchased":0
        },
	extendModel: function(Model) {		
		_.extend(Model.prototype, {
			requestProduct: function(identifier, success) {
				Storekit.requestProducts([identifier], function (evt) {
					if (!evt.success) {
						alert('ERROR: We failed to talk to Apple!');
					}
					else if (evt.invalid) {
						alert('ERROR: We requested an invalid product!');
					}
					else {
						success(evt.products[0]);
					}
				});
			}
		});
		
		return Model;
	},
	extendCollection: function(Collection) {		
		_.extend(Collection.prototype, {
			// extended functions and properties go here
		});
		
		return Collection;
	}
}

Thinking about changing "appleid" to "vendorid" to not make it Apple specific but haven't taken a look at Android InApp purchases yet.