Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.
OnGuardHelp - Travel & Location
Sleep as Android - Common alarm clocks ignore your sleep cycles, they wake you on schedule no matter your are currently in your deep sleep. Waking up from deep sleep is unpleasant, it makes you tired and it may negatively affect your productivity during the whole day.
Crystal Alarm - Mobile phone alarm A personal alert strengthens your safety in risky situations, threatening situations and for lone workers.
Pillow for iOS - An iOS companion that helps you sleep better 💤
Emergency Alert - Alberta Emergency Alert