I'm building a similar tool system-wide for OSX. There are a couple differences in my implementation: - It handles short words by allowing the space key to ove

I'm building a similar tool system-wide for OSX. There are a couple differences in my implementation: - It handles short words by allowing the space key to override the suggestion. - It uses arrow keys, tab, and enter (Sublime completion style) to choose the right word or phrase. - It starts with a basic dictionary, and learns from frequent words and phrases you type. - It draws new words and phrases from open documents and web pages, and optionally from Google's auto-suggest.