Cool! Let's try this.
> 1. Write down the apps on your phone or computer that you use the most. If you want to bootstrap a profitable business, I recommend listing the apps you use for work.
Emacs, vim, xterm, tmux. (I use them all for work. 99% of the time, what you see on my screen is either Emacs, or an xterm running tmux and some instances of vim.)
On my phone, alarm clock. (I use it to get up for work)
> 2. Write down the one feature for each app that you use the most within that app.
In emacs and vim, probably self-insert-command or some basic motion commands.
In tmux, switching between windows and panes.
In xterm.. uh, just the fact that it's a terminal?
Alarm clock. I use it to wake me up in the morning.
> 3. Write down what slightly annoys you about that one feature
Nothing about the most used features above annoy me. Well, terminals annoy me but emulating terminals is the raison detre of a terminal emulator so I don't know if there's much you can do about it..
I also hate alarm clocks but I kinda need one to wake up.
> 4. Build the product around the one feature you feel you can cook up quickly and that will benefit your workflow
Looks like it wasn't that easy :(
Something tells me that picking the most used application and the most used feature in it most likely leads to the most solved problem that doesn't need to be solved again...