This browser app adds Pinyin romanisation to any Chinese website or EPUB, but some work better than others. Tested on, but not affiliated to, JW. ORG and the Watchtower Online Library Chinese pages Annotation is performed by your device itself: this app does not send your browsing through any third party.
According to the antivirus report, the app is safe and secure. Referenced Expressions is the official developer of Pinyin Web & EPUB that can be found in the Books & Reference category. The latest update of this application was launched on Nov 12, 2019 and the tool has been installed by over 10K users.