I was asked to organize a hackathon for schoolchildren. This hackathon will be held for three days. All children are high school students and winners of Olympiads in Informatics.<p>I am creating educational program consisting of mobile app development and web app development. I need your advice on selecting actual tools for both parts. We can assume that children has no prior programming experience except of programming in Pascal at school.<p>For mobile app development I want to use MIT App Inventor. I think that it is right tool for quickly prototype their mobile app. Learning Java and Android SDK for three days is unrealistic.<p>And for web app development I have no idea. Rails? Django? Flask? NodeJS? First I need to teach them Ruby, Python or JS. Apart from that I have to teach them HTML/CSS/JS and basic concepts of web.