edit: of course ideas that are doable for an average programmer :) and the only thing stopping you from doing those at your own is a lack of time.
I've long wondered why there isn't an app that turns cell phones into functional TTY machines for the deaf and hard of hearing. Like many of us, the deaf community has cell phones, but unlike many of us, they still need TTY machines for many functions. These tools are not cheap, being over $100. I see no reason the functionality can't be emulated cheaply, or for free, by smart phones.
Currently turning on TTY modes on a cell phone only enable hearing Baudot tones. An app should listen to the phone call, interpret the Baudot tones (at a paltry 45 baud at worse, but there are proprietary and alternative protocols[0]) into text on screen, and then transmit Baudot tones at the same rate when typed.
If you can figure it out (I'm sure there's a reason why it isn't done already,) then I'm sure you could charge a few bucks for it. Figure there's ~28M deaf people in the US? There's plenty with cell phones, especially younger people.
Such tech could also just receive Baudot and send voice (VCO; Voice Carry Over), and receive voice and send Baudot (HCO; Hearing Carry Over). It could even be used for cell to cell TTY calls, letting the deaf and hard of hearing communicate using minutes instead of texts or data.
[0]http://en.wikipedia.org/wiki/Telecommunications_device_for_t...
My honest assumption is that there's a reason no one has made the app that replaces hundred dollar equipment... But I haven't found the reason yet.
thanks.