CAE

http://www.flo-joe.co.uk/

https://www.teachers.cambridgeesol.org/ts/

Writing:
http://www.flo-joe.co.uk/cae/students/writing/index.htm
Student makeovers:
http://www.flo-joe.co.uk/cae/students/writing/makeover/archive.htm

Online practise test (sample)
http://olpt.s3.amazonaws.com/online-practice-cae/index.html

CAE Writing on Prezi