[kbruner]

It sounds like this company is firmly founded (a year old, spending money, etc), so asking to become a co-founder at this point isn't fair to founder(s). Seeing as you've also been paid for the work you've done so far this seems like an amazing generous offer. Also think about what a different candidate would accept as CTO, which is what must happen should you decline.

[joslin01]

No, it's certainly not firmly founded. The business plan has changed within the past couple months and it's been iterated over a lot. There was a prototype developed, but it's just given to investors for them to look at and is very basic / stripped down.