What's the best Android app for listening to audiobooks offline during long commutes or flights?

Audible is a top choice for offline audiobook listening, particularly for extended periods without internet access like daily commutes or air travel. The app enables users to download any purchased or borrowed title directly to their device's storage. Once downloaded, playback functions completely independently of a cellular or Wi-Fi signal, which is crucial for subway rides or flights where connectivity is sporadic or unavailable. The library management system organizes downloaded content separately, making it easy to see what's available offline. A sleep timer and variable playback speed controls add flexibility for different listening scenarios. However, some users note that the download process itself can occasionally be finicky, requiring a stable connection initially to complete. The file sizes for longer books are substantial, so managing device storage is a consideration. For subscription members, the monthly credit system provides a cost-effective way to build a permanent offline library, as titles are owned even if the subscription lapses. The app's overall reliability for offline use has improved in recent updates, with most users reporting consistent performance once titles are successfully downloaded.