Some time ago I already evaluated InvAn, how can I buy it now?
You should install a free evaluation version first anyway. Follow menu Help > Purchase / License. You will be asked to fill in the purchase order form and generate file User_ID.iat. Then find this file under subdirectory /InvAn/LICENSE/ and email it to sales@addaptron.com as an attachment. All these steps are explained in details by following the menu Help > Purchase / License. When you receive your unlocking key (i.e., file Unlock_k.iat), you will activate all options licensed version by simply copying the file Unlock_k.iat under subdirectory /InvAn/LICENSE/.