Hey Trevor,

great second post.

I agree with most of what you say but have to point out that you left out a big technique: search trends.

what you describe is finding apps that are already there and competing against them.

A different approach would be analysing search trends and match against niches with no apps.

For example, I remember discovering that paddling was a huge "industry" (as a sport) with ZERO apps.

For this, you would use services such as SearchManSEO or mobileDevHQ to identify niche "hotness" or the oldschool SEO way using GoogleTrends/Keywords.

hope it helps, Giacomo