Mobile applications (apps) have gained an increasing importance in the field of software engineering as they are becoming one of the most widely used type of software. In the Android ecosystem, obfuscation tools are available to optimize, reduce the size and protect the intellectual properties of apps. However, despite the clear advantages provided by obfuscation most apps do not use it, often because of the difficulties induced by the usage of obfuscation which requires writing rules to keep a usable app. In this paper, we identify the concrete challenges encountered by app developers who wish to use obfuscation in their apps. In addition, we propose an approach using crowdsourcing to automatically generate rules, when static analysis is not sufficient. With the knowledge gained from hundreds of projects, we hope to lighten the burden on developers when writing rules.