Des Moines investors Tej Dhawan and Sheldon Ohringer have made an undisclosed investment in Erin Rollenhagen's Entrepreneurial Technologies, which provides custom business application development aimed at mobile and web platforms. Rollenhagen will remain CEO, and Dhawan and Ohringer will serve as advisers and partners. "Our clients' requests for more projects and increasingly specialized development led me to look at what we wanted to be in five years," Rollenhagen said in a statement. "I once was told that the best companies grow when the market demands it, and when approached about a possible investment by leading local angels, I knew the time was right." Rollenhagen started the company in 2007, and said it has grown steadily.