This app is for those who understand Vim and unix.

DroidVim is a Vim clone text editor ported for Android.
Vim 8 (huge version multi language) grep diff and ctags are ready to use.

▼ Required - ARM (Android 4.1 and up) x86 (Android 4.3 and up)
Features:

▼ External storage support - External SD card USB memory GoogleDrive Dropbox etc. (Requires Android 4.4 and up)
▼ Special Keys - Esc Ctrl Tab Arrow keys and more.
▼ Direct input - Disabling predictive text and/or auto correction for normal mode.
▼ Clipboard - Clipboard commands ("*p "*y) are supported.
▼ Custom Font - Use your favorite monospaced font.
▼ Touch to move - Touch swipe flick to move cursor.
▼ Multi language - Vim with multi byte option iconv and multi language messages.

Extra features (in-app purchase):
▼Git - Version Control System.
▼Python - Programming language.

Appendix:
DroidVim is an open source project.