Organize email in mailboxes on iPhone - Apple Support
iOSComponents - iOSDataGrid - The most powerful DataGrid for iOS applications and iOSControls - AutoCompleteUITextView, Combobox, Date Combobox, CheckBox, RadioButton, CheckBoxList, MultiSelectCombobox and more!
What control should I use to indicate multi-select lists on iOS? - User Experience Stack Exchange
iOSDropDown on CocoaPods.org
Create an iOS App - Box Developer Documentation
Chosen with select-option on iOS · Issue #1233 · harvesthq/chosen · GitHub
iPhone/iPad: Drop down with size property allows to select multiple options. If shows the count of selected items.