This is a really bizarre chain of comments to me. It's great that you're proud of your work, but an external module is a clearly superior product. First, not everyone has a mobile phone at all. And you can't wear it everywhere you go, especially not in 2009 when the battery might have lasted a few hours at most. You still can't take it in the shower with you. You can't "wear" it if you're not wearing clothing at all. Even newer mobile phones with longer battery life still need to be set down somewhere to charge every now and again and can't stay clipped to your hip permanently. And you inherently need a mobile phone per user. An external module can detect every person in a room falling. They don't need individual sensors. Care facilities and at-home care personnel can use this when people in their care and not themselves are the ones at risk. And this things costs 1/30 of a mobile phone.
The only claim I can agree with is an app-based fall sensor is a good option for people who already have mobile phones and don't trust external modules and would prefer to just use something they already have. You seem to have concluded this is widespread based on your users telling you they felt this way. You have to understand your users are not a random sample of all people at risk of falling. They're very obviously people who had mobile phones and thought something like this was a good enough idea to try.
The only claim I can agree with is an app-based fall sensor is a good option for people who already have mobile phones and don't trust external modules and would prefer to just use something they already have. You seem to have concluded this is widespread based on your users telling you they felt this way. You have to understand your users are not a random sample of all people at risk of falling. They're very obviously people who had mobile phones and thought something like this was a good enough idea to try.