Have you ever asked yourself, when submitting an app to the playstore and seeing a crash rising on your crash report : « If only I could deactivate this feature so I could correct the crash without impacting the users » ? Well, wonder no more ! There is a solution for this, and it’s called « feature toggle ». Some well-known websites are using it, but few on their mobile apps. At BlaBlaCar, we’ve been bold and implemented it inside our mobile apps.The main purpose of this improvement is to be able to activate or deactivate little features inside the app on the fly, without resubmitting an apk on the playstore. It can be used in case of crashes or when rollouting new features to a small group of users. In this presentation I will explain you how we defined our vision for this system, designed and implemented it inside our Android app.