Two ways :
1- Withdraw all : From the homescreen, click on your savings account. There would be 3 buttons at the bottom : "Add Money" (with a purple + icon), "Withdraw All" (red icon with an arrow pointing downwards), and "More" (a gray icon with 3 dots).
2- Transfer : From the homescreen, press "Pay" (an orange icon with an upward arrow, at the bottom of the screen). Then input how much you want to transfer, then click on "Choose recipient". Then select your current account (or whichever account you want to transfer to). On the final screen (where the button says "Send Payment"), on the top left hand side, you have your "origin" account (which by default is your current account). Click on it, and select "Savings". You can now see you can transfer from "Savings" to whichever destination account you selected. You can click on "Send Payment" and voila!
