18. A non-transitory machine-readable medium having stored thereon machine-readable instructions executable to cause performance of operations comprising: generating, for display on a display device, a payment graphical user interface (GUI) comprising a list of contacts of a user; providing, via the payment GUI, a payment indicator comprising an image of a selected contact from the list of contacts; receiving, via the payment GUI, a touch input that is associated with the payment indicator; determining a transaction amount based on a time-dependent measurement of the touch input; and providing, for display via the payment GUI, the transaction amount along with the payment indicator.
18. A non-transitory machine-readable medium having stored thereon machine-readable instructions executable to cause performance of operations comprising: generating, for display on a display device, a payment graphical user interface (GUI) comprising a list of contacts of a user; providing, via the payment GUI, a payment indicator comprising an image of a selected contact from the list of contacts; receiving, via the payment GUI, a touch input that is associated with the payment indicator; determining a transaction amount based on a time-dependent measurement of the touch input; and providing, for display via the payment GUI, the transaction amount along with the payment indicator. 19. The non-transitory machine-readable medium of claim 18 , wherein the time-dependent measurement of the touch input indicates a speed of the touch input.