Connect the budget sheet
This page only talks to your Apps Script. Put the web app URL in config.js as APPS_SCRIPT_URL. It should end in /exec. The spreadsheet id and the PIN stay in the script, not in this page.
Unlock this phone
Enter the PIN stored in the Apps Script project. It stays on this phone and is sent with each update. It is not your Google password.
New receipt
Use the camera or a screenshot. The picture is shrunk on this phone, then read for the store, date, and peso total.
Try a sample receipt
Recent receipts
Add to Home Screen from Safari or Chrome to open this like an app.