Houston's seen plenty of on-demand delivery services in the last year, starting with grocery-delivery company Instacart, to courier services, to alcohol on-demand.
The concepts are pretty straight-forward. Users can order something, be it groceries, beer or documents, via their smartphone, tablet or Web browser. In a short amount of time, that service or product is delivered to you if you're within the company's delivery range. Costs might be slightly higher to compensate the driver, but these services?