Combining a Pomodoro timer and a to-do list is a great concept. I especially like how you can customize your Pomodoros (I prefer longer work periods and longer breaks). However, this app has a crucial quirk: the timer stops whenever the app loses focus or the phone goes to sleep, except if the phone is plugged in. In the settings, be sure to check "prevent screen lock" as otherwise the app wont run in the background.