If you click on the following links, you can download lots of exercises.
1. Burlington - Present Simple (+key answers)
2. Burlington -Present Continuous
3. Burlington - Pres. S. vs. Pres. Cont.
4. Pres. Simple and Presnet Cont.
5. Pres. Simple and Pres. Cont. (2)
6. New Inspiration - Present Tenses and adverbs