Generally not used unless it is part of a phrase like "a Tangomp4 converter" or "an atypical Tangomp4 file". To give you the most accurate answer, could you tell me:
Is a software program, a file type, or a person's username? Tangomp4
When using Tangomp4 as a proper noun (e.g., "I am using Tangomp4 to convert this file"). Generally not used unless it is part of
When Tangomp4 refers to a specific, unique entity known to the audience (e.g., "I downloaded the Tangomp4 update"). a file type
Based on the context of Tangomp4 being a proper name, file format, or product, here is the proper usage of articles: