UnivNote
Turn PDF textbooks into a place to solve problems and test yourself.

UnivNote is a PDF note-taking app for studying with iPad and Apple Pencil. Extend page margins for calculations, keep solutions on a layer you can hide, match page numbers to your printed book, and revisit recorded explanations by tapping the handwriting made during a recording. Up to 20 notes are free. Unlimited Notes costs $9.99 once in the US, with no subscription or ads. iPhone and Mac are also supported.

App Store: https://apps.apple.com/us/app/univnote-lag-free-pdf-notes/id6763764042
Privacy: https://ryuznro.github.io/univnote-legal/privacy
Developer: Jeonghwan Ryu
US pricing checked October 2, 2026. See the App Store for current local pricing.