Been using it for years on my Mac. Recently moved to put the iOS version on my phone and pad. Tried to use the sync via iCloud. I think I got it to work ONCE. Maybe twice. Then nothing. Talked with support about it at one point. We got it to sync again.
The thing about using snippets though is the file for them is a living document. It changes (obv) every time you add a new snippet. So I let it go for a while and I (finally) notice that things are not the same on ANY of my devices. 2 MacBooks, a Mini and a couple iDevices. Check and the sync is off. Yet again. Spent a few hours over the last few days trying to make it sync again. Annnnnnnnd NO DICE.
Switch the sync over to DropBox? Syncs in less than 2 minutes on everything. I suspect a security setting in iCloud hexed it up.
I've sent a note to Smile Support today to confirm, but thought if anyone else was having an issue they might like a short term solution via DropBox.
This is nearly as bad as 1Password Support not being able to trouble shoot that it didn't update under anything except Safari... Trying to update the App through FireFox was making me crazy. And them too apparently, because I handed them the solution. They were ever so grateful...