Features of obtaining the source code of the application written under Android OS are considered. Most reverse engineering methods focus on automatically extracting information from the source code without taking external human knowledge into account. Most often, however, important external information is only available (for example, developer knowledge or domain knowledge) when human knowledge is used. Much of the knowledge about software systems is implicit and therefore difficult to recover with purely automated methods. There are types of information that are difficult to detect only in the source code, and this problem is solved by additional human knowledge. Typical approaches to the justification of data include coding an explicit meta-model and expressing analyses at that level.