Virtual versions of real O-Level Science (Chemistry) Practical Tests. Do the experiment on the bench, but — just like the real exam — you record every observation and calculation in the laboratory notebook, and it's marked like the actual paper.
Epsom salt: find x in MgSO₄·xH₂O by heating, then identify the ions in mixture B. Observations are recorded by completing dropdown sentences — great scaffolding for a first attempt.
The same practical, but you write every observation in your own words — the notebook marks them offline against the real mark scheme's points and tells you what's missing. Exam-realistic.