I'm using a refurbished Sony Xperia Z2 with Android 5.1.1 Lollipop. I'm also firmly entrenched in Apple's iCloud eco-system and am a multi-platform user (Android, iOS, OS X).
Part 2: Email
If you don't use any iCloud aliases then just use the stock email app on the Android device. Stop reading now. It's that simple.
I use an iCloud alias to shield my true Apple ID. Whilst not particularly any more safe or secure, it helps me feel clever.
However most Android email clients do not give you the option of using iCloud email aliases. There are ways and means though (and over time I expect more and more Android email clients to support iCloud aliases).
This was actually particularly easy for me. I've been using Gmail as my back-end email for almost 10 years (Google remembers so I don't have to - I just have to be good with search keywords, which I am).
With Gmail I'd already setup my default sender address as one of my iCloud aliases. So on Android I can just use Gmail and my outgoing reply-to address defaults to that alias.
More recently though I believe Gmail have made it more convoluted to add additional email addresses (aliases with differing domains) to your Gmail account. So I don't particularly recommend it unless you want to use Gmail as your backend.
A simpler method for people who keep their email on iCloud and don't forward it anywhere is an app Aqua Mail.
The free version doesn't support iCloud aliases (identities) but reportedly the paid version does (I say reportedly since reviewers say it does, I have not tried it myself - go and read the reviews for yourself).