Try the app called AppShopper. You can search for what is new, most popular, you can search for free apps, etc. you can set up a wish list, and it will notify you when an app you want to buy goes on sale. Based on your question, I found a new app called SayHi, which provides translations from English to quite a few languages and vice versa. It was also on sale today for US$.99.
This is a lot easier than searching for apps in the App Store