Android: Every phone comes with built-in alarms, but AlarmPad is a new utility that makes them more useful. You can set contextual, personal alerts that show you calendar appointments before and after, the weather at the alarm time, or even recurring alarms that Android's default clock won't let you set.
Android's default clock has alarm features, but if you need to set alarms with greater or more sporadic frequency than it allows, you're out of luck. AlarmPad lets you configure alarms for any frequency or recurrence you prefer, lets you add notes and additional information for each alarm, and even lets you set alarms for your calendar events on your own schedule. The app also detects when you create a calendar event, and offers to create a notification for it.
When you do set an alarm, AlarmPad shows you relevant information for the alarm time, including the weather, and any nearby calendar appointments that you might want to know about when the alarm goes off. When you dismiss an alarm, you'll see a notifications view that shows you that information again, and if you prefer, AlarmPad will speak the information aloud. Similarly, AlarmPad can be used with voice commands, either to set your alarm or to dismiss it.
The app also integrates nicely with Tasker, so you can hook it up with other apps, and supports DashClock, so you can see and manage your alarms from your lock screen. AlarmPad is free at Google Play, but you can only have five alarms set up in the free version. The full version will set you back $0.99.