I'm just doing this because I don't think I need to download and install several MBs of an app just to do this routine.
A deployed version is available at http://imtired.isgeek.net/. I suggest using it from your phone and adding it to the home screen.
- Offline mode support, so no need for connectivity to use it.
- Small foot print. No need to download several MBs
- No installation (It's a shortcut to a website, no need to go through an app store)