Opentracker automatically supports offline measurement. You do not have to configure your app to track events while offline. If a user’s tablet, phone or device loses signal or disconnects from internet, data is queued on the device to be sent later. Once the connection is restored and the device comes back online, the cached information is sent for processing and the user event stream from the offline period is collected.
My app doesn't work offline
You can still collect interesting information even if you app only works online. This is because many app users switch methods of connectivity, for example, from service providers to local wifi networks, work/ home, etc. Automated offline reporting functionality ensures data is collected during changes in connectivity.