Future Simple

http://www.ego4u.com/en/cram-up/grammar/future-1-will/exercises
http://www.saberingles.com.ar/curso/lesson18/06.html

Immediate Future exercises

http://www.englisch-hilfen.de/en/exercises/tenses/going_to_future_mix.htm

http://perso.wanadoo.es/autoenglish/gr.going.p.htm

http://www.englisch-hilfen.de/en/exercises/tenses/going_to_future_statements.htm