I agree completely with @tjohns first point, if you're calling out UX as a top point then you really should have screenshots. You should have screenshots anyway.. I dislike having to download something just to see what it looks like. Not having screenshots just makes the barrier to entry higher.
Second point, you really need to make sure spelling is correct (i.e. "celluar" should be "cellular"), that degrades the perceived quality of the product. If I see spelling mistakes on the landing page then I assume there might be other kinds of mistakes... like in the codebase for instance.
Your product looks great. Just had a brief skim over your main page and have seen one grammar error... "We understand that every second counts when you're on the field." should be "...in the field.".
I would recommend ensuring grammar etc is correct, as this could easily turn away potential customers, regardless of how great your product is.