Public Q and A app that allows people to ask questions during presentation using their smartphone. The app would connect to the central system where you would be placed in a queue. When it time for you to ask your question, you would be alerted on the app, and you can either stand up or remain seated and ask your question into the phone. The sound would be transmitted over the internet and amplified through the event's system. It's important to keep latency as short as possible in this system, and have good filtering to prevent echos. First Steps: see what other solutions are already on the market and why they are not used more often.
Live video app for events. This is a complementary idea to the above. An app that allows participants to stream live audio and video from the even to their phone over local WiFi network. This would allow better accessibility for people with pour hearing or eyesight, and allow people to stay tuned even if they get up to go to the restroom, etc. The system would come with a free app and an encoding server that runs locally to minimize latency. First Steps: see what other solutions are available, how this can be achieved with low latency.
Debate Tube, a youtube like service that allows anyone to debate anyone else on any subject. The debates would be held live, like on twitch, and would have either 3rd party or automated moderation. Participants can monetize their participation in the debate through advertisement, viewer support, or prizes, depending on the format. First Steps: see if this exists, if not, make it. With today's political climate this could be a useful tool for democracy.
Inspiration of the day app. Ok, to be fair, I am stealing this idea, at least in part from my brother in law. He is working on something similar right now, but I would design it with a twist. An app that shows you once a day inspirational or ironic fullscreen image. The app is free, but you can monetize it by allowing once a week a company to make a inspirational picture that somehow also features their product. First Steps: check out the competition, see what else is out, pitch this to my brother in law.
Event buddy, an app that allows you to find people near you who are also interested in going to the same events you are interested in going to. You can carpool and make new friends. The app would simply show event's around you, and show you profiles of people who are nearby you and are interested in same events. This is perfect for university campuses. First Steps: see if there is something like that on the market right now, and build a prototype.
Rubik's Cube solving app that allows you to take pictures of all 6 sides of the Rubik's Cube and it shows you how to solve the cube via 3D animation on your phone, with explanations. Basically, there is only 8-10 moves out there, and once you learn them all, you can solve any cube really fast, but it's easier to lean with animations. First Steps: look into possible 3D frameworks and think about possible monetization ideas. Probably advertisement only, or a paid app.
Start a company that makes drones that look and act almost identical to birds, like crows. While the technology isn't quite there yet to make a perfect bird replica, it should be possible to make an artificial crow that can maintain altitude by gliding and flapping it's wings. It can have a prop in the back for gaining altitude. Sell this to the military and law enforcement, for surveillance applications. First Steps: research the possibility of making a prototype that can gain elevation by flapping it's wings or use a propeller silently, to make it as realistic as possible.
3D printed halloween masks. With Apple's new face scanning technology the iPhone can create some extremely accurate 3D scans of your face. This technology can be used to create custom fitted silicone 3D masks. There are companies that are already catering to high end mask aficionados. Make an app that they can brand, and have their clients use to scan their faces. First Steps: contact one of these companies and see if they are interested, assess the value of the market.
Doctor office documentation app. The idea is simple, you scan a QR code on the top of the doctor's office check in form, and that loads all those forms, an a mobile friendly format, into your phone. The app will remember answers to all of the commonly asked questions, and will allow you to sign on all the right lines using your finger on your phone. The app will also read to you using text to speech all of the disclaimers and such, if you chose to do so. Once done, you would submit the form, and it would instantly pop up on the computer of the person doing the check in. This saves time for the patient and the hospital, and reduces mistakes. First Steps: see if this exists, pitch this to a few hospitals, see what they say.
Universal signature app. This is also similar to above, only it's for collecting political signatures on local proposals. You see someone promoting some kind of cause, scan a QR code, and that loads their pitch material, video, etc, into your phone. You can review it later and digitally sign the petition if you like it. People's identity can be verified using driver's license, if necessary. First Steps: check if this complies with legal requirements, pitch this to Change.org