To login, you must first create a Kraken account if you do not already have one. You can do this by registering on their homepage and continue to create an account. You can also make an account in the app if you prefer to use the app only, which is available for both Android and Iphone.
The big advantage of Kraken is that the fees are very low. For maker orders this fee is maximum 0.16% and can even be as low 0%. These are the orders that are filled directly without entering the order book. For taker orders the fee is between 0.10% and 0.26%. This is quite a difference in comparison to other brokers. Naturally, depending on how much you trade fees get lower as well.
Kraken is a fiat to crypto as well as a crypto to crypto exchange. The disadvantage of Kraken is that it is not possible to pay with Ideal, which could be a limitation for some users. After creating an account, you can deposit fiat into your account via bank transfer and will be processed within 1 business day. When the money is transferred to Kraken before 9AM, the coins will be deposited into your account the same afternoon.
There is also a Kraken app available iOS and Android. The app can be downloaded from the app store or google play store. The app is not very extensive and looks a bit outdated. The overviews of your funds in the app are also less clear. Still, if you really like Kraken the app can be used to set buy and sell orders and you can see exactly which coins you have and how much fiat money is still in your account. Although the website is much better, the app can be a great addition to have a quick look or to set up some trades.