http://www.learnclick.com/

Create Gap-Filling Exercises

Take any text, mark the words you want to learn and learnclick.com transforms your text into a cloze deletion test.
SMILE
Multiple-choice
True/False
Drag/Drop
Sentence Mix
Paragraph Mix
Cloze
Multiple-Select
http://www.teachingenglish.org.uk/gap-fill-generator
Use this gap-fill generator to create texts for your classes: simply choose your level, topic and text, create your worksheets and then print them!
http://www.gnowledge.com/?AspxAutoDetectCookieSupport=1

Gnowledge is a free-to-use education platform where everyone can create, publish, share and take tests, exercises and assignments.

http://www.proprofs.com/quiz-school/
is a good site, and you can make great online flashcards there, too.
http://www.classmarker.com/
is a good to go to just create basic online tests. It’s simple, efficient and effective.