Design a App Icon for a currency calculator but with a new twist.

Netnotion (Do not use this name for the App title or relate to it)

Our website is new, HTML5 currency calculator.
This calculator runs on unique domains in 8 countries and in 4 different languages.
We are working on a redesign of our current website.
Also we want to bring our fast and easy to use calculator on the mobile phones via this HTML5 web app.

Keywords are finance, currency, exchange rates.

Our target are people who need to do simple currency conversion (not for brokers or people working on finance) like tourist or online shoppers.

We need an app icon.
It should fit to the restyling of the website. Attached are images of the flat design of the site.
We do not want a typical currency icon like a small calculator or round arrows. Please come up a fresh approach to a currency calculator. Either way need the icon be self explaining and international understandably because of the different language version of the calculator we will offer.
The icon should reflect following keywords: easy, fast, simple use.
The design should be very clean, simple and flat. We like the Material Design as inspiration.
Attached examples of four icons we do not like and and four icon we like the style.
The Icon should support different sizes, ranging from 48 pixels up to 512 pixels.

Think of:
- Currencies (dollar, euro, any)
- Countries
- Shopping
- Travel