I’m way overeducated and have studied in a lot of fields. Here’s some study aids I’ve used for the sciences.
High School Chemistry Guide
This app costs US$1.99 and is a great guide to high school chemistry concepts covered in all levels of high school chemistry. It covers content and terms and has multiple choice quizzing (shareable) for learning.
Nutrition & Vitamin Study Aid
This app costs US$1.39 and has 500 terms and concepts in nutrition, vitamins, and biochemistry. It has quizzes, flashcards, and glossary (and you can share results with friends).
Weights and Measures FREE Guid
This free app has over 1000 units of Metric, US, and English weight and measurement. Great explanations and illustrated study guide. Recommend.
Physics study guide
This app coasts US$9.99 and goes over a huge amount of Physics subjects at a high school, college, and graduate level. Chapters include: Laws of Science, Classical Mechanics, Heat, Gas, and Thermodynamics, Electromagnetism, Optics, and Atomic Physics. Tons of appendices. Recommend!
This app costs US$0.99 and is a good reference guide for calculus split into the main categories of basics, derivatives, and integrals – and each of these categories has a number of subcategories. Broadly useful. Recommend.