Hello @molly7,
Welcome! 
I hope you don’t mind that I upgraded your question into a topic of its own- things tend to get buried in the comments of old threads, so this way I hope it can get the attention it deserves! 
I use an Android, but hopefully some fellow coven members who use Apple will have some recommendations for you.
In the meantime, I’ll drop a link to the Lucid Dreaming Guide- it’s more resource material than tools per se, but maybe there’s something there that might help you on your journey.
Lucid Dreaming - How to Control Your Dreams
Wishing you all the best with your studies - blessed be, Molly!