A couple ones on my list:

Distraction blocker — Chrome extension that helps you block distracting parts of websites (such as the Youtube home page). Sort of a generalized version of Kill News Feed, which blocks the Facebook news feed.

Blue Apron for Hobbies — Helps you adopt a hobby with less of an overhead and research requirement. Bundles up the necessary equipment and information to help you learn the skill, sending you a weekly package and linking to instructional videos.

Lie detection app — See if you can detect lies using computer vision (more of a research project, not sure if it's possible)

Yelp for Github — Chrome extension that lets you rate and view ratings of Github repositories (beyond just the number of stars and forks that Github shows)

Rock climbing app — App that overlays various rock climbing routes onto an image of a rock face using computer vision.

Healthcare idea: build video consulting platform to let patient reach doctor anytime, anywhere, no need of travelling to doctor office. Of course this one is for non-serious-cases such as mental health, Dermatology or Nutrition Advice.

Similar platform such as http://www.babylonhealth.com/ or http://www.doctorondemand.com/.

A simple reporting app for automatically creating reports and diagrams from a database.

- point-and-click interface for designing reports

- easily share report templates with coworkers

- usable by non-technical people

- low barrier to entry (easy installation, low price)

Most reporting software I've seen is geared at "enterprise"; terrible to use, or to license. I think there's an opportunity in this space at the low end.

Open Amazon Echo type device using arduino and open web service that sets up and forwards text to different registered webservices. If text matches some regular expression(or some other way to parse it) then forward it to this web service.