A variety of regional languages from various tribes in Indonesia, especially in eastern Indonesia, especially the former Sorong Regency, Sorong City, West Papua which is inhabited by the Moi tribe with their local languages. The regional language used by the Moi tribe is the language "Moi". Moi language in the past for hundreds of years has conformed itself to, the language lingua franca (language of instruction) in all peninsula birds of the island of Papua. The reduction in language speakers in tune with the erosion of the cultural values of the Moi tribe, in the end the culture of the Moi tribe which will become a reflection in various aspects of national and tribal life gradually diminishes its influence. Even though it contains a variety of local wisdom which is very noble "Language Shows the Nation". A great nation will always have and try to maintain various aspects of its culture and will try to preserve culture through recording inherited from ancestors. The Moi tribe which is a medium of communication for the Moi tribe in daily life is mainly used for communication between the eight Moi sub ethnic groups themselves and even migrants, so that if someone wants to go and live in some of the districts above, then he must learn to use the Moi language in order to be able to communicate with the Moi people properly and correctly. For migrants and native Moi people who cannot communicate with Moi, they can use tools such as the Moi dictionary as a translation tool, but translation dictionary books in Moi are very rare and even almost non-existent.
The use of the Moi language has also experienced a decline in daily communication, especially for the younger generation and the Moi people who live in and outside the region. So that the Moi language is one of the regional languages in Indonesia which is almost extinct because it is rarely used and not implemented in the world of academics namely; used as subjects or majors in the Moi language literature in schools and colleges. By looking at this situation it is to facilitate someone in learning the Moi Language, an Moi language dictionary application is based on android. The purpose of making the Indonesian-Moi dictionary application is as a tool help to make it easier for users to know the meaning of Indonesian vocabulary translation into Moi and vice versa, as well as to preserve this language so that it does not disappear because of the times.