ZotPad tries to make a new release two or three times a year. The development roadmap can be followed at GitHub.
Each new milestone contains a small number of major features. The main focus of the following three releases are
1.3: Annotating PDFs in ZotPad and adding new items and attachments.
1.4: Full text indexing and searching of PDF files.
Starting from 1.3, there will be two versions of the app: ZotPad and ZotPad Student. Because the annotation feature will be implemented with a commercial third party software library, parts of ZotPad will closed source. ZotPad Student will contain only open source code and will also be released for free in the App Store. There may be some other limitations in the student version.
Development roadmap is adjusted based on user feedback. You can participate on the UserVoice pages by suggesting features or voting on existing features.