I would personally avoid coinbase. Its a very good app, easy to use and deposit funds. But withdrawing it, thats another story.
I had a little dabble, just to test the water, my £30 investment had grown to £50 in a short time. So, to make sure everything works ok, i went to withdraw. So i cashed in the bitcoin/litecoin to GBP within the app, for a fee of £1.99 per currency. So now my £50 is down to £46. Ok, lets get this cash out, except there is no option to withdraw GBP, it has to be euro (it doesn't tell you this when you sign up). but to do this i need to convert to a crytpo and then into euro, incurring a £1.99 for each. Now down to £42. So, to confirm my bank account I have to make a deposit to coinbase, in euro. Now this incurs a bank charge for the transaction, £9. now down to £33.
Now i know once the bank is confirmed, it isn't charged again so the next transaction will be cheaper.
great for purchasing, nightmare to withdraw, in the UK anyway.
And, as other people have mentioned, the app shuts down when the price drops significantly. It took weeks to get verified.transactions don't register sometimes so your'e not sure whether to hit buy again or wait and see if it did actually work.