A free app for Android, by Color Apps HBN.
The Greek Keyboard app lets you write in Greek and switch between the two languages easily. There are several themes to make the keyboard look prettier and more fun, and you can customize it according to your personal preferences.
Additionally, the app provides auto-correction and word prediction so you can write in a fast and accurate way.
Moreover, this keyboard allows you to type in Greek words without the need to switch to another language. You can also copy and paste Greek text anywhere on the keyboard.