What apps do you use to read Manga?

Tachiyomi is awesome! Each site (Mangabat, Mangafox, even nHentai) has its own catalogue that can be installed into the app. It is also not just manga sites, other comic sites have Tachiyomi support. The only issue I've had is that when a manga site is taken offline, you need to load a new catalogue and re-save all your mangas to your bookmarked Library collection. The Library function is cool because it gathers everything you are reading across all catalogues in one place