I do not recommend this app, because for many phrases, romaji does not fit the phrase in kanji/kana at all! In most cases, the romaji version is the shortest and the most simple one, but not always (e.g., no - kekko des - いいえ).
I dont know what the authors intention was, but thats just weird and makes no sense.
filachan about Japanese Language Guide & Audio - World Nomads, v1.1