'LowPoly' is a free, very basic Launching Soon template with a 3D polygon background. The HTML template features an AJAX sending sign up form, a countdown timer and 10 different color schemes to choose from. Simple but an easy start with little budget. (we have a $2.95/month hosting special - perfect for a quick announcement of your next idea)
LowPoly is fantastic simple and clean bootstrap coming soon template. Simple design is nice. It is really easy to use and configure. Find more info about resources used here.