Please note that your funds must be on the trade balance to place an order.
In order to place an order, you need to go to the Markets tab in the application, using the search, find an available trading pair and tap on it.

Next, you will see a window with information on the selected trading pair. At the bottom of your application screen, you will see Buy and Sell buttons.

By clicking the Buy/Sell button, you will be automatically transferred to the Trade tab. In the Order Type line you can select a suitable order among proposed (limit, market, stop-limit, stop-market).

After you have selected the type of order, enter the required data: price, quantity (additional stop price for stop-orders). The Total line will display the amount including the fee.
Click the Buy/Sell button.
All is done!

Depending on the type of the order, it will be executed immediately or if conditions specified by you are met (for stop orders).

You can track its execution/cancel in the All orders tab. To do this, click the list icon in the upper right corner of the screen in the Trade tab of the application.