I’ve tried out the Web Books Viewer, and I can say that it works really well offline, even on Android! No need for Chrome, which is cool, as it’s pretty lightweight. I love that I don’t have to install anything, and the app’s great for keeping my library on the go. As for limitations, I’ve had some issues with annotations and bookmarks while offline—nothing major, but it’s worth noting. They seem to get stuck on the device you’re using, so syncing them later can be a pain if you switch to another device. Still, if you just need a simple offline reader, it’s definitely worth it!