Don't Break Your Flow
Do you need to focus on a task? Do impending deadlines interrupt your flow? LunchTime Timer can help.

When working on a document or code I find it necessary to get into 'flow'. Flow is a state of high concentration which can be difficult to maintain. Nothing disrupts flow like having to remember an appointment or an obligation.

LunchTime was written to help with cooking but it can also help improve concentration. Setting timers for cooking and reminders for appointments removes a major source of preoccupation and worry. With a little practice responding to the timer's alarms won't break into your creative flow. (I find kneading dough is a great opportunity to just think for ten minutes.)
Getting Things Done
This is consistent with ideas from Getting Things Done (GTD), a popular productivity book by David Allen. GTD suggests downloading everything from your mind onto paper or some other organizational system.

LunchTime Timer allows you to delegate forthcoming events to the timer and simply forget about deadlines. This works so well I set timers for all kinds of events. With the timer running I can focus on my work with 100% concentration.
The Problem With Devices
One major drawback of using software like LunchTime is the danger of distraction by the phone itself. If you find yourself distracted by your phone then switch on LunchTime's Lock Screen mode, then you can access the timer without unlocking the device.
I need to keep my phone nearby for urgent calls so setting aside my devices is not an option. I tend reduce notifications to an absolute minimum. Then I use LunchTime in Lock Screen mode for cooking and to remind me about urgent forthcoming events. My phone only distracts me when I want it to.