if you could only have one payed app in each category, what would they be?

So, if you could have all the free apps on your iOS devices that you wanted to have, but you could only have one payed app in each category, what would they be? For example, 1 payed app in navigation, 1 lifestyle app, one medical app, 1 game, 1 utility, one weather app, one entertainment app and one productivity app, what would they be? The apps could be any price, but you could only have only one payed app in each category and you could have as many free apps in each category as you wanted. Which payed app would you get for each category?

Forum: 

#1 Social networking:

App Developer

I opt for Whatsapp. The app receives frequent updates and does not have major accessibility issues. In fact, it is the only paid app which I would not want to live without. /Roland

#2 Voice Dream Reader

I use this app every day to read non-DRM protected books. The choice of voices is very good and at about $2 each not expensive. The app is very well laid out and the developer works hard to make the app as accessible as possible.