I forget who said it first, but there's a saying that if you want to look for business ideas, look for where people are complaining about sharing Excel files.

I forget who said it first, but there's a saying that if you want to look for business ideas, look for where people are complaining about sharing Excel files. That's where they've accidentally built an application that they need (giving you a spec) but which isn't good enough for the job (giving you a way in).