Ember is a small addon that changes the behavior of the default equip manager at the bank.

The equipment manager at the bank ordinarily treats the bank like another set of bags: equipping something from the bank will swap what you were previously wearing to the bank. So once you leave the bank the previous gear is inacccessible.

Also while at the bank, right-clicking an item in your bags moves it to your next free bank space. Right-clicking an item in the bank moves it to your next free bag space.

Ember makes the equip manager behave like the latter. When you swap gear at the bank it swaps to free spaces instead of equipping them and abandoning your previously worn gear at the bank. This allows you to use the bank as a place to temporarily store gear and still swap among multiple sets out in the field.

The specific changes are:

When you hold ALT over a character sheet slot, in the flyout buttons that appear:

Green borders mean the item is equipped.
When not at the bank, the flyout button behavior is unchanged.

While at the bank:

Blue borders mean the item is banked.
Selecting a banked item will move it from bank to your bags.
Selecting an equipped or bagged item will move it to the bank.
Hitting the 'Unequip' button will empty that slot to the bank as well.
When at the equipment manager tab on your character sheet:
The set tooltip is now more descriptive and lists what's in the set.
Sets with a green title are equipped.
Sets with a red title mean at least one item is missing.
When not at the bank, the tab behavior is unchanged.

While at the bank:

Sets with a blue title are banked, meaning at least one item is in the bank.
Clicking an unbanked set will make the 'Bank' button light up. Clicking this will move the set to any available bank space.
Clicking a banked set will make the 'Withdraw' button light up. Clicking this will move the banked items to any available bag space.
Double-clicking a set will either bank or withdraw depending on its banked status.
If an item in a set going to the bank is shared with other non-banked sets, it will not go to the bank. It will only bank when all the other sets that contain this item are banked. You can hold CTRL while swapping to override this behavior.