for Android

Some more background information...
Several languages are supported, e.g. Polish >>
There is also ComboKey-Fin if you like.
The latest text entry method by Tiptyper, the developer of GKOS keyboard.
ComboKey (app to try the method) and ComboKey Plus (default keyboard) can
be considered as examples of optimized chorded keyboards. A chorded keyboard
(or a chording keyboard) increases the number of characters available by applying
combos, that is, key presses where two or more keys are involved in some way,
as opposed to just simply having more buttons to get more characters.
Just to test:
Since Jan 21st, 2015, ComboKey
A concept demo app is available in Google Play:Get it from here.
Recommended for daily use:
Since April 20th, 2017
ComboKey Plussystem keyboard
(free) is found in Google Play: Here
Versions for older phones available here >>

Some history in this picture:
Picture: ComboKey button themes on Nokia N9 (64 GB MeeGo) and Nokia 6 (32 GB Android)
ComboKey for Meego and Android (Android 2.3.3/4, API 10, GINGERBREAD MR1 or later)
With ComboKey app, you can tiptype text in normal to huge font, easily,
on big easy-to-hit keys, with one or two hands, left or right handed,
in landscape or portrait orientation of the device. Even touch type!
(Android 4.1.x - API 16 up! Versions for older phones here>>)
With ComboKey Plusapp, you can use the same method for text entry
with all your applications that require the default keyboardfor text input!
(Android 3.0 - API 11, or above)
- tiptyper (developer of the app)
More - Forum - ComboKey on Facebook
Privacy Policy for ComboKey Plus >>
Latest stable published packages available in Google Play:
Google Play: ComboKey v1.4 since 28th June 2017
Google Play: ComboKey Plus v2.2 since 8th December 2017
Draft v5.7beta or later is here for testing: ComboKey Plus (.apk)
Draft v5.2 upgrade for testing: ComboKey Basic (.apk)
Some native versions are found here.
Older stuff:Legacy GKOS test v1.1.0beta (.apk) - ComboKey 1.5 beta (32-bit only)
Another old Legacy GKOS app: GKOS v1.0.5b