If you need mobile access, you can find the SIMATIC WinCC OA UI APK on specialized mobile app repositories. How to Get a Trial Version
New Online Documentation. Starting with WinCC Open Architecture V3. 18, an online version of this documentation will be available, wincc oa 3.18 download
Detailed release notes and critical patches (like the recent P034) are available on the Siemens SIOS Portal . If you need mobile access, you can find