We identified our core features & strengths. Quick patent searches on these let us know whether there is something out there identical or similar to what we are doing at a macro scale. Keep in mind, patents are worded in lawyer-speak so we can't say there is nothing out there until spending a lot more time & resources (lawyer money).

It is fairly common to find that little things you do are patentable so focusing on the big things will keep your task manageable.