As coders, we have an enviable ability to create platforms and apps that bring people together. The world is not short of challenges right now, especially climate change, but we will only have a real impact on the world if we can help people unite and organise to pressure those with power and influence. Chris and his husband quickly developed an app ten years ago to allow ordinary people to lobby the normally inaccessible and unelected House of Lords to pass the Same Sex Marriage Bill. It unexpectedly took off, with 15,000 emails sent in the space of two weeks, helping the Bill overwhelmingly succeed in the normally-socially-conservative upper House of Parliament in the UK. He'll talk here about how he did it, and how you - an individual with a computer and knowledge of how to knock an app together - can use this skill to give a voice to the voiceless, and to potentially change or even save the world.