Hi!
I've found this forum after searching for some app for the iPhone and I saw this post

So, I'm using an app that its available on App Store for iPhone and iPod Touch called "Lucid Dreams", it has informations and tips about lucid dreams and in particular it looks on Reality Checks. It has an alarm for reality checks, you can set a desired time interval choosen from some that the app offers (like every 30, 60, 90 minutes, etc), and it will show a popup and ring a sound at the choosen time (day and night of course)
I hope I was clear with the explanation xD
The link of the app on iTunes is this: [CENSORED] <--- I see that I can't post links until its passed at least one week since membership
Maybe reading there you can understand better the functionality of the app, or you can read searching on App Store / iTunes for the name of the app

I hope I've been of help pointing you here, it seems that this is what were you looking for!
I'm using the alarm also for try some other techniques besides the RC, for example using self-hypnosis sentences during the day every time I hear the ring, or for remember me to think that I'm dreaming during the day (as stated by the oriental yoga of dreams' and tantrism techniques).
Now I haven't much time, maybe later I will open a post under the general section to explain me better if someones is interested to it

Greetings