To access On-Demand Geofilters, go to Settings in the app, find the option and choose a template based on the occasion. You can personalize the design by adding stickers, emojis and even tweak whatever text is on it, but forget trying to make anything too risqué. Snapchat still has to approve your creation before anyone can use it. The ephemeral messaging app says it'll take a day to review your submission, and if it passes muster, you'll get a notification telling you how much it'll cost.
If it's the first time you're making a Geofilter, take note you'll have to indicate the area you'd like it to cover -- that's why it's called Geofilter. The amount you'll have to pay is based on how big that area is. For instance, the $6 minimum payment will make your overlay accessible within an area that covers a couple of houses, enough for a small July 4th BBQ with family. While the feature is only available in the US at the moment, Snapchat says it'll roll out in the UK, Canada, Australia, Brazil, Saudi Arabia and United Arab Emirates "soon."