Grammarly - Clear, effective, mistake-free writing everywhere you type.
PhraseExpress - PhraseExpress is one of the best and most fully featured text expansion apps available to Windows users.
Hunspell - Hunspell is the spell checker of LibreOffice, OpenOffice.
Beeftext - Beeftext is an open-source text substitution tool for Windows.
DSpellCheck - Yet Another Notepad++ Spell-checking Plug-In
TextExpander - TextExpander: Communicate Smarter. Gather, Perfect, Share Your Knowledge. Recall your best words instantly, repeatedly.