Rate Assistant is an exchange rate app, which provides real time rate and exchange rate timeline. Android version only supports rate search now, other functions will be added in the future.
Submit issues on https://github.com/MuShare/Rate-Android/issues.
You can download this app from Google play Store: https://play.google.com/store/apps/details?id=org.mushare.rate
iOS version is also open source in Github: https://github.com/MuShare/Rate-iOS.