"Smart Keyboard" - There is a Trial version in the Play Store.
I will likely purchase "Smart Keyboard Pro" for $2.64 once the Trial period is up.
There are also Language packs, so be sure to DL the "English" pack or whatever language you prefer. There are several to choose from. Or you can put several languages on your KB and switch between them if you type in more than one language.
Once installed from the Play Store, you just go into "Settings" > "Language & Input" and tick the "Smart Keyboard Trial" checkbox, then touch the "Settings" Icon and adjust the KB Settings to your liking.
The best features are that the size of the keys are user adjustable and the user can also select from various styles of KBs such as iPhone, Android, Gingerbread, Galaxy, HTC, Grey, White, Black and there is also an option to DL more Skins.
I prefer the "Galaxy" style KB.
Of course it has the usual other features - key preview pop-up on key touch, vibrate, sound, key press duration, spell check, text prediction, long press for special characters, and even a "Calibration" feature that has you type a common phrase to improve your typing accuracy and a bunch of other features.
I will have to DL more Skins, but I like this KB very much and I highly recommend it.
YouTube vid review:
Smart Keyboard App Review (What's The Apps) - YouTube