It raised $7.2 million for an app that allows users to book interior or exterior next day painting for a home, office or store. The average Paintzen user spends at least $2,500 per order, according to Mike Russell, Paintzen chief executive and founder. To provide professional painting services, the startup works with companies ranging from mom-and-pop shops with just a few employees to large companies with upward of 100 professional painters on staff.