Luno is bitcoin company that provide wallet,exchange and API service to the costumers.You can exchange your bitcoin directly from your wallet to Naira and back to bitcoin but some little fess are applied.it has exchange platform where you exchange bitcoin to Naira just like bittrex and other exchange platform.
How to open bitcoin account
1.click here to sign up Invite | Luno
2.you can sign up with your email,facebook or google account.
3.choose your password and country
4.click sign up
5.comfirm the email sent and you are done.
You can also watch this video below