You can easily implement a column-picker UI using the grid's columns property, a ListBox control, and Wijmo's showPopup and hidePopup methods.
For example, the grid below starts with an auto-generated set of columns. Click the gear icon at the top-left cell to show a ListBox where you can select the columns you want to display.
Also you can use the grid's columnLayout property to allow users to save and restore column layouts. Click the "Save Layout" and "Restore Layout" buttons to see how this works.