- Update the website visuals/design, they seem a bit dated
- Put the download buttons on the front page to increase conversions
- Make a mobile version, especially for tablets. Most tablets nowadays seem powerful enough for your software, particularly the iPad. I'm sure you've thought of this before, and I have no idea what the competition is like. However, as a home owner, I can tell you interior design apps have 0% of my mind space. They should probably have more, especially considering that, combined with sites like Wayfair, IKEA, and Overstock.com, you can have a design --> purchase pipeline which is both convenient for consumers and beneficial for you via referral revenue.
Also, this isn't really a suggestion, but something I'd personally love: Machine learning interior design. AutoCAD already has ML structural design tools, and this would be simpler than that. Make it so that a consumer can enter their parameters (room layout, cost, visual style preferences) and your "artificial interior designer intelligence" generates 10 designs that the user can mix and match from. The designs would link to the cheapest seller of each piece of furniture. Alternatively, the user can manually select the main pieces of furniture, like the couch and TV console, enter their parameters, and the virtual assistant will suggest matching "in fill," things like couch pillows that people usually neglect or just purchase randomly whatever is on sale. Augmented reality viewing of the machine-generated designs would be the cherry on top and prepare you for mass market introduction of AR glasses.