The iPad is a great device for translations and multilanguage dictionaries. Because it is frequently "in your pocket" and because the device is connected to the Internet for regular updates, it works extremely well for trips out of the country. Unfortunately, not every app provides the same high level of translation quality that you might hope for when away from home. Portos Dictionary is one such app -- offering an uneven, poorly executed experience in serious need of an upgrade.
The Portos Dictionary is labeled as free and so should be expected in some ways to lack a few functions. However, the basic interface is nearly impossible to use. When you open the app, all of the words are presented in a single, long list. Start typing in the search bar and the list will move toward the word you are typing in English. The problem is that this free version includes only words that start with A and the English list is alphabetized according to translation, so it's not even always the word you are searching for. Definitions are limited as well, with only a short line for each, and there is no way to access other definitions beyond "A" without a paid upgrade.
There are certainly more complete international dictionaries on the App Store, even if they require a paid upgrade. Portos Dictionary would only be useful in a very limited number of circumstances, and even then, it would lack the interface to be truly usable.