Great calculator by an unethical company. This company has begun the process of converting their best selling apps to a subscription basis - if you are on 'A'nother platform, 2 months ago they began charging a subscription price that costs 2X PER YEAR as you can buy the app for, right here, right now! Advice is to either buy the app now before that happens here, or choose to not support a company that states "operates with integrity" while demonstrating the opposite with corporate greed.