You may need a special font to display the diacritics properly: this would require root and instructions are <a href="http://anewtab.com/install-hindi-marathi-devanagari-fonts-in-andriod-phonesdevices">here</a>. Standard QWERTY keyboard layout with Pali and Sanskrit diacritics and Pali dictionary (about 75,000 of the most common word-forms in the Pali texts). Install https://f-droid.org/packages/com.menny.android.anysoftkeyboard first, then select the desired layout from AnySoftKeyboard's Settings->Keyboards menu.