This is the only Swahili dictionary for iPad that includes info about the noun class for a given word (an important detail for this language). Other dictionaries don’t include this, so you are left to guess the class, sometimes guess incorrectly, and therefore use the wrong prefixes on your verbs and adjectives.
It’s also great that it works offline - I used it a ton while on the plane to Kenya to make sure I knew the right words for what I wanted to say!