Please make an undo button

Using it for more than 6 yrs. Its best in UI and simple to use. Vault feature is awesome. Some glitches are present in recent updates where any cursor is placed in a notepad, the view window goes to irrelevant view and only when typed, it shows the exact place scrolling again. May be this will be covered in next update. Also include more icons for categories as the set available is there for years and longing to get updated..