I don't buy a lot of apps for my Android phone. In fact, the only money I spend on apps comes from Google Opinion Rewards (a "free" app which adds money to your Google Play account in return for filling out surveys -- in other words, for making myself a more marketable product for Google to sell to advertisers). I've so far spent the princely sum of $2.98 on Sleep Cycle Alarm Clock -- 99 cents for the app itself and $1.99 for a one-year subscription to the related web-based service SleepSecure, which maintains more statistics than the basic app (even though SleepSecure is web-based, it's purchased through Google Play as an "in-app purchase").
Damned if I'm going to spend three bucks on something and not get a blog post out of it. I'm happy to report that this is a positive review (and not an affiliate commission kind of thing -- they're not paying me, I paid them). There's a lot to be said for this app (which you Apple lovers will be happy to know is also available for iOS -- here's the company web site so you can pick your poison). The app really has three features, one of them so far as I can tell completely unmentioned in the developer's promotional language but very important to me personally.
Feature Number 1: It tracks sleep cycles and rates your sleep quality.
How does it do this? Through your phone's accelerometer. That's the gizmo that detects the device's orientation and is also sensitive to motion (other apps use it to let a phone act as a pedometer and so forth). The iPhone version of the app, but not the Android version (yet) can optionally use the microphone instead of the accelerometer. People to tend to move more or less frequently and more or less actively depending on how deeply they're sleeping. You place the phone near your head (under the bed sheet but NOT under a pillow or anything else that would substantially hold in heat that builds up) before going to bed (there's a test mechanism you can invoke to make sure it is detecting motion; if not, place it differently). After each sleep the app produces a graph showing your state of wakefulness/sleep over the duration of the sleep. The optional SleepSecure subscription keeps stats for longer and offers more analysis of the data the app gathers. No, I can't speak to how accurate or scientific all that is. But anecdotally, when I do remember waking up during the night, the app does seem to reflect that fact and the timeframe correctly in its overnight graph. And it also seems to reflect, in its "sleep quality" report, whether I got a good night's sleep or a crappy night's sleep.
Feature Number 2: It's an alarm clock. Belay that -- it's a GREAT alarm clock.
Instead of just telling Sleep Cycle Alarm Clock what time to wake you up, you can choose a range of time in which to wake up leading up to the final time. For example, I get up by 4:30am each day, and I have the range set to any time in the 30 minutes prior. The app looks at my sleep state and picks a time within that range when it judges me closest to wakefulness already, so that it's not startling me to groggy wakefulness from deep sleep if it's possible to avoid doing so.
It starts off with a gentle, user-chosen tone and gets louder over time. If I want to "snooze" I just touch the phone instead of having to hunt for a button -- and there's a setting for set snooze time or "smart snooze." In the latter mode (which is the one I use) it tries to figure out the NEXT optimum time, within a reasonable range, to start trying to wake me. From my viewpoint, this feature alone is worth the cost of the app. My previous alarm clock was my "digital assistant" beeping at me and urgently telling me to "wake up!" Annoying, even though I chose that assistant's usually pleasant female voice. Sleep Cycle Alarm Clock is much less discombobulating.
Feature Number 3: This is the undocumented one. The app makes sure I don't forget to charge my phone overnight.
Maybe it's because I'm just still not used to being a smart phone user yet, but I've had a bad habit of going to bed and waking up the next morning to find that my phone is nearly drained because I didn't think to put it on the charger overnight after a full day of (to one degree or another use). Which means that if I need to use the phone for anything, especially if that means taking it somewhere with me, I have to plug it in and wait.
Sleep Cycle Alarm Clock may work without the phone being plugged in to the charger. I don't know because I haven't tried it that way. The instructions say to connect it to the charger before going to bed. So I moved the charger to the outlet behind my bed. When I set my alarm clock, I am also charging my phone as a side effect. Each morning I wake up with a fully charged phone. Once again, that's an effect that's well worth the 99 cent app price to me.
A sort of sub-feature that's in between the cycle detector and the alarm clock functions: The user can use a "sleep aid sound" -- 13 options ranging from ocean waves to rain to wind to white noise, I use "medium wind" -- as a lullaby. The sound can be set to fade out "intelligently" (that is, when the app decides you're asleep), or to run for a certain amount of time, or even all night. Pretty sweet in my opinion.
If you want to use your smart phone as your alarm clock (that seems like a reasonable thing to do -- why have a separate device?), and if you want an app to analyze your sleep so that you can experiment with ways to routinely get a better night, and if you want to never worry about forgetting to charge your phone overnight again, Sleep Cycle Alarm Clock is 99 cents (or $2.98 with the useful add-on) well spent.