It has interesting bounty campaign. And can I participate in only one stage?

No, you can participate in any stages

What do you meen? I want to participate second stage, but I do not think about third, becouse it is very long. Can I get benefits from secound?

I think you were told about this. You can only participate in one stage and get your tokens.

This is a good option for both the project and the bounties. I wish success to the project

Me too. But I would like to look at the prototype itself and not its description. I would use this service for sure.

SteshaScott