I have used Keynote on the mac for most of my prototyping needs. I help teams come up with a really cheap prototype as part of the design thinking experience and we have used keynote for both desktop and mobile prototypes. It supports clickable actions and some amount of animation with magic move. Here is a great video from WWDC 2014 where they talk about the how. https://developer.apple.com/videos/play/wwdc2014/223/ If you need help, give me a call.

In general, I would say that the best way to improve the experience and increase conversion is to test and see what works. By that, I mean, change something, and see how it affected your user's experience. This assumes that you are tracking user activity on your site, with something like Google Analytics. Also, assumes that you have have enough traffic so the measurements are statistically significant. Another place you can possibly improve on, is to make sure the content is what the user is looking for. There is the experience of consuming the content, and there is the content itself. Does it make it compelling for somebody to spend the time on your site. For this, I would do testing as well, by talking to your potential users and understanding what they need.

I would say that instead of going wide, go narrow. Get some quality feedback to fine-tune the product. What I mean by that is, show your product/prototype to people you already know and get their feedback [ignore if you have already done that]. Make the product so compelling that they become your "marketers". Can you show it to some extreme users - somebody who would absolutely love it or hate it? Get their feedback - see what triggers them and incorporate that into your product if you can. This way, when you go spend the budget you have on marketing, you have a better chance of success. Also, the feedback will help fine-tune the messaging that goes with your marketing. My experience is with Design Thinking, where you are are constantly empathizing with your user and getting their feedback to fine-tune your prototype. Also, the focus is on delighting the user. My thoughts above come from that experience. Not really the marketing answer you wanted, but will help you fine-tune the message when you go market. Hope that helps and best wishes!