There are plentiful of Dictionary apps on iOS/Android, to name a few :-
https://play.google.com/store/apps/details?id=fr.nghs.android.dictionnaires&hl=en
https://play.google.com/store/apps/details?id=com.bravolol.bravolang.englishchinesecdictionary&feature=search_result
https://play.google.com/store/apps/details?id=com.movinapp.dict.enes.free&feature=search_result
https://play.google.com/store/apps/details?id=com.sedevelop.dict.enesen.free&feature=search_resultWhere do they get the dictionary data to make those apps? Do they license them from somewhere or there's an open available data?