Elizabeth Ferguson’s website: IELTSliz.com
The site has free resources for the test. It is targeted for levels 7, 8, and 9 but all the examples are relevant to anyone taking the test. With over 300 pages the site is extensive and useful to any teacher of IELTS.
IELTS Test marking: IELTS public speaking band descriptors
The table on this link shows detailed criteria for speaking levels.
This is a free tool students can use to hear how they would sound with an American accent. The student records their own voice and then the website will create a "golden speaker voice" which is the student's voice with a natural American accent and rhythm.
Ding, S., Liberatore, C., Sonsaat, S., Lučić, I., Silpachai, A., Zhao, G., Chukharev-Hudilainen, E., Levis, J. and Gutierrez-Osuna, R., 2019. Golden speaker builder–An interactive tool for pronunciation training. Speech Communication, 115, pp.51-66.