Every time you pay a visit to the App Store to feed your app craving, they are waiting for you: the one star reviews from upset customers or most of the times, total jerks. The only element that developers can't control on their app page is actually the juiciest and often makes you realise that we were all trolls in a previous life. Comments from customers who have downloaded an app and took the time to leave a star rating or even write some words have to be one of the biggest headaches for iOS developers.
If you chose to do so, you'll be informing other customers about your bad experience hoping that they avoid buying it in a desperate aim to reduce the developer's income stream until they update the app with a fix to make you happy. In my experience in the App Store, and please correct me if you haven't seen this too, customer rants in the ratings can't be really justified in most cases. Why complaining about a game not running on your first generation iPod Touch when it is clearly stated as not supported? Why slashing an app if it is obvious from the app description that it is only available for US customers?
Apple doesn't make it easier for developers, since they can't moderate or reply to customer reviews. The worst thing is that the usual suspects forget to change the rating if the app actually gets a bug fix solving the problem.
My point here is that if you are out of kindergarden and are about to write an App Store rating, please think twice: is it something that belongs to support? Then the App Store is not the correct place to raise it. Are you going to write a review stating your personal experience, pros and cons? Then continue reading. A simple guide to become an App Store review champion could be summarised in one sentence: don't be a jerk!
☆ One star - Very poor - The app fails to meet its promise in many different ways. Any good aspect of it is shadowed by its poor execution, memory hogs and slowness due to lazy coding and general lack of creativity. Compared to other alternatives, and being free is not an excuse, it would easily be the worst.
☆☆ Two stars - Poor - The app certainly delivers and "does what it says on the tin," but in ways that are counter intuitive, odd and require too many steps. The inclusion of unnecessary features only highlights the lack of focus of its creators. Despite being functional, it behaves like a webapp and probably doesn't stick to Apple's human interface guidelines. You regret buying it and cannot recommend it.
☆☆☆ Three stars - Average - The app works solving an everyday problem and you find yourself when you need help. It meets your expectations although it felt really rough when you first launched it and could be immensely benefited by some polish in both user interface and graphic assets. You tend to hide it on a folder in your springboard. You didn't buy an iPhone or iPad to be average.
☆☆☆☆ Four stars - Good - The app is substantially better than competitors despite a probable high price, but it is a pleasure to use. You find yourself using it every day but understand that it could be replaced one day by something better. You often show it to friends when they ask about cool apps and have checked other apps from the same developer hoping to see the same standards.
☆☆☆☆☆ Five stars - Excellent - The app is one of the top three of its kind and stands as a strong contender in its segment. It excels in functionality and has best in class design and usability. The sort of apps you keep recommending to friends when they buy an iOS device. Developers keep releasing updates to make it even better and if you had to, you would buy it again. You are still surprised how Apple didn't come up with this first.