You can create a fully functional web app for iPhone and Android devices just by creating a simple model of it in Excel. This ordinary user is testing his new web app on his phone, with the design still showing in Excel on the large screen.
With the new price model, you get $200 worth of free pageviews every month. If your credit card expires, your Google maps will stop working on your website. You should set a calendar reminder to update the expiry date every time you get a new card.