It's true. That's the first thing one should check on while investing into an ICO. Well said with that, and I have found at least three such ICO which are having working model prototype. One us nexus social project who are having social platform just like Facebook but more or less direct selling of your product and services ad you would do with advertisement on the Facebook. The application is complete and running well on the site, smartphones and all compatible devices. That makes the ICO more trusted and believe it or not they hit the success when they launched there ICO. Another one is jibre network who is having awesome concept of converting your traditional assets to digital one with their platform. Both are good one and best until now. The working model which is what made them successful.