Will vs. Going to

http://www.englisch-hilfen.de/en/exercises/tenses/will_going_to_future.htm
http://www.rafamoreno.com/Rafa/Goingto.htm
http://www.better-english.com/grammar/willgo.htm

Present Continuous for future vs Be going to

http://www.tolearnenglish.com/cgi2/myexam/voir2r.php?id=13478
http://www.englishexercises.org/makeagame/viewgame.asp?id=7103
https://www.montsemorales.com/gramatica/Futurtenses.htm

Present Simple and Present Continuous for future

http://www.myenglishpages.com/site_php_files/grammar-exercise-future-plan.php

FUTURE MIXED

https://www.ego4u.com/en/cram-up/grammar/future-mix/exercises
http://www.englisch-hilfen.de/en/exercises/tenses/future.htm