Well first off, it needs an about section that tells me in clear, concise terms what it does. I'm not going to sign up for something if I don't understand what I'm getting into. Especially if that something asks me for my mobile phone number.<p>From the front page, as best I can make out, the only way this could work would be if I text some number an expense every time I incur one. That's going to cost me money (or a text from my plan) and if I can do that, then I can just make a note for myself and enter it into a spreadsheet later. But I can't do that, I'm usually too busy to make a note of what I just spent. Much less text it to somewhere.<p>That said, it's sort of a neat idea. And I'm sure it could be useful for some people - people more conscious about money and less absent minded than me. Get that about page up with a clear description of what it is and how it works. I would test it, but I'm in Thailand and don't have a phone right now.