I still have Aldiko Classic on my ancient Android 4.x phone (screen 4.3") for testing that a new style / table / image works on a tiny screen. I have to delete the books in Aldiko before updating with Calibre. While the ancient phone can still install much from the Playstore, not any longer Kindle, Kobo etc. Kobo won't install on Android 6.x, though Lithium and Kindle did. Everything works on Android 8.0
I have KO Reader rather than Lithium (direct APK download) on my Android-ish Mars eInk. But Lithium on the 7" Android 6.x and 10" Android 8.x tablets.
I use Xodo for PDFs and images that are one page docs on Android Tablets.
|