I’ve tried plenty of apps, and my absolute favorite for offline access is 'Moon+ Reader.' It’s super customizable, supports a ton of formats, and lets you download books for offline reading. The night mode is a lifesaver for late-night binge-reading sessions. Another solid option is 'Google Play Books,' which allows you to download purchased or uploaded books for offline use. If you’re into audiobooks, 'Audible' is a no-brainer—just download your titles and listen anywhere. These apps have saved me during long flights or subway rides where Wi-Fi is spotty.
For manga and comics, 'Tachiyomi' is a godsend for offline reading, though it’s Android-only. 'Kindle' is also reliable if you’re deep into Amazon’s ecosystem. The key is finding an app that fits your reading habits—whether it’s speed-reading novels or savoring comics frame by frame.