Web AppBuilder for ArcGIS (Developer Edition) 2.9 beta version is available in Early Adopter Community. It syncs up with the latest Web AppBuilder in AGOL June 26th update. Click on this link to access the 2.9 beta version.
Developer Edition 2.9 has made enhancements on multiple widgets. Now you can set relative time span and intervals to animate live data with Time Slider; filter multi-selection on a single field; swipe multiple layers at a time; honor zoom scale for the line and polygon feature search; move a point feature to manually entered coordinates or GPS location with Smart Editor; edit many-to-many related records; measure areas in 3D, etc. See the blog.
Please use the Forums within the Early Adopter Community to communicate all your observations and feedback.
The Web AppBuilder for ArcGIS team