I want to create an iOS 10+ Swift app. Some of the features include persistent local data storage on the device, backup of user's data (text and images) as well as data sync between user's devices.
I'm currently thinking about CloudKit + Core Data combination, but I don't think it is the easiest option and I can't find any up-to-date tutorials on this techs working together. Can someone suggest better options?
Realm is a very good option I use it myself and its very easy and very quick! Also they update their code very offen and they have their own documentation. It can also be used by other programming languages such android so if you will develop an android version of yours you will follow the same path.
Here is the documantation You can install it manually or via pods If you're going to do it manually follow the instructions on this video And check the next ones for a quick start of how you use this.
Hope it helps. Happy new year.
Don't forget to accept the answer if you been helped.
EDIT
Check here for icloud and whatever question you have you can ask here or open an issue on github so they can helped you.