Twenty: Stand up every 20 mins

Even if you live an active lifestyle, sitting for long periods of time can lead to build up of excess fats and cholesterol in your body. People who work desk jobs sit for hours at a time, without getting up at all. Even if your ride your bike to and from work, all that time in a chair is affecting your health. However, you can fight the effects of sitting by standing up for 2 minutes every 20 minutes.
Twenty is a very simple app. Once activated it will remind you stand up and move every 20 minutes. When you sit down at your desk, simply open Twenty and pull down on the switch to activate your reminders. Every 20 minutes you will receive a simple notification prompting you to stand up.
Twenty has been specifically designed so it can provide you with notifications, even when you are using other applications without burning down your battery. It uses a passive alarm system that doesn't run constantly in the background so you wont need to worry about it hurting your phone's performance.
** v1.1.3**
- Added a new setting for vibration on the notification. This was a user requested feature. They emailed me and I delivered.
- Still no ads.
- Still free.
** v1.1.2**
- Fixed notification to read in minutes (not minutes, lol). Sorry guys!
** v1.1.1 **
- Minor bug fixes
- Added "donate" button
** v1.1 **
- Added ability to change interval
- Added ability to change ringtone
- Fixed some underlying bugs
- Still no ads
- Still free