I noticed how little reviews I had received on my apps compared to the number of downloads. While other apps had hundreds of reviews. After researching more, I realized that most of those were from paid reviewers or their own employees (in case of large companies). To even the playing field, I created the App Reviews Exchange - a place where app developers can review each others apps and mutually benefit. The platform works on a karma model so that it can function without a monetary transaction i.e. you earn karma when you leave an app review and your karma is used up when some one reviews your app.