Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
xCurrency - Smart Currency - A simple ads-free currency converter.
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
CurrencyScoop - Developer-friendly REST API with real-time and historical currency exchange rates for world currencies and cryptocurrencies.
Better Uptime - We call you when your website goes down
Cocorate.com - Online currency and cryptocurrencies exchange rates calculator helps you convert anything in real-time.