Today I have published a new open source project on GitHub, called DKExpandableSelectionTree. It is a better expandable list view for Android that allows user to select multiple items from a tree of objects. You can clear all selections, you can select and deselect multiple items by selecting a whole group. It also displays a number of selected items inside a group in parentheses after the name of a group.
This is how it will look in a sample project, when you clone the repository and run it: