I think that focussed on the killer app is the wrong strategy at this time. Smart glasses are in the early, gimmicky, not quite right not quite ready for primetime stage in it's evolution. To be more specific, Tik Tok is a killer app, Pokemon Go was a killer app, but they only worked as killer apps because they were on a killer device. Think back to the first iPhone, it wasn't actually the first smartphone even though a lot of people thought and continue to think it was. It was just the first smartphone that was actually appealing, useful, and easy to use. Focusing too much on a specific application is not going to get you far when most people still prefer to pull out their phones for what they need than some glasses they got as a gift from their techy early adopter kid or grandkid that feels more like a toy than something useful.
Smart glasses aren't at the Tik Tok and Pokemon Go stage, they're still at the pre-iPhone stage. You don't want to be the killer app right now because it's too early. Now is the race to be the killer device, the new iPhone equivalent. For that you need to make a device that is stylish, comfortable, useful, and intuitive to use. Make the experience feel the opposite of gimmicky, make it feel natural. Make it as simple and as meaningful to use as pulling out your phone to tell the time, look up directions, read a text, and snap a picture.
Basically you're not competing with other smart glasses makers for the best app, you and all smart glasses developers are still competing with the iPhone for best device and particularly best device experience. Until using glasses can compete directly with pulling out your phone, all these cool little extras are just a gimmick. Make a product as easy and simple and intuitive to use as a phone with all the same or similar use cases, and then build up more to what phones can't do.
