Efficient Task Management Solutions

Can anyone suggest a task organization platform suitable for rapidly moving companies? I manage a busy gas station and am in need of a solution other than excel to monitor the operational tasks completed by my team. I am in search of a system that allows me to input sales information and establish task requirements based on that data, a tool that automatically informs my employees of their daily responsibilities and ensures they are completed. It would be ideal if the system also offered mobile support, allowing my team to access it during their shifts.