What's the best Android app for annotating and highlighting PDFs?

PDF Reader is a strong option for users seeking to annotate and highlight PDFs on Android, thanks to its focused feature set. The app includes tools for highlighting text in multiple colors, underlining key passages, and adding sticky notes for comments, which is particularly useful for students reviewing textbooks or professionals marking up reports. Users can also insert freehand drawings or shapes to emphasize sections, and the interface is designed for quick access to these functions without clutter. Real-world scenarios include researchers annotating academic papers or business teams collaborating on draft documents, where the ability to save annotations directly to the PDF ensures changes are preserved. Reviews indicate that the highlighting feature is responsive and customizable, though some users note that performance can slow slightly with very large files exceeding 50MB. Despite this, the app handles most everyday tasks reliably, and its offline capability means annotations can be made without an internet connection. For those needing a straightforward, no-fuss solution, PDF Reader balances functionality with ease of use, though it lacks advanced editing like OCR text recognition found in premium alternatives.