For Vtiger CRM, I have developed a simple widget for exchange rates. The widget integrates with the service of the Central Bank.
The widget contains settings, you can get data on exchange rates for a certain date, you can select the currencies that you want to see on the page.
Appearance is a very simple, native tiger interface.
Installing the widget is very simple, it comes with a separate module. After installation, on the VtigerCRM main page, in the "Add widget" tab, a new line "Currency Rates" will appear.
The widget is distributed free of charge, to receive the module, just contact me in any way convenient for you, I will send it as an installation archive for VtigerCRM