Ian Addison found Spelling Shed:

• Moderately improves attainment“Children are more eager to learn their spellings. The online games and tests encourage them to keep trying and they have been really engaged. ”
• Significantly reduces teacher workload“Having a whole spelling scheme has helped us massively. Our previous spelling scheme had ideas but didn't provide resources but Shed does. This has helped me organise weeks worth of spellings in minutes. ”
• Slightly saves school money
• Moderately provides school data“It has helped to improve the summative assessment of spelling in my class. I have a good handle on how well my children can spell (in tests) and we use this alongside the spellings in their books and in their writing. ”