Running Bitceldi on a laptop that's 3yo+.  Getting 2.5 coins every 1-4 hours with just 2 cores running 20-30 H/s. Very simple to setup just install the wallet, sync (back it up).

Has a mining tab built into the wallet even a pool to join. Then select how many cores to use.

As for smartphones I've used faucet apps. Mangocoins and miners gate. I don't use them much and don't recommend them.