SearchImprove has a built in spell checker which can be set to operate in several different ways.

• Automatic error correction to the dictionary's first proposal
• Automatic error correction if the search gives 0 results
• Did you mean …?-view, which suggests one or more alternatives to the entered words.

Additionally, the search engine is set to use stemming (search for all grammatical forms of the keyword), and wildcard (*) for more letters and (?) for one letter.

The settings for this function can be accessed under Setup → Package → Language settings and spellchecking.