Looking for a solution to create multiple alerts throughout the day to help keep me focused and on task with my Android phone.

Question about scheduling an alarm or alert of some kind that would help me keep focused and on task. This may sound simplistic but I have some focus issues and looking toward ways to keep on track. Searching for an audible solution but there may be other solutions I am not familiar with. I was thinking a beep or .wav or mp3 clip that would remind me to check in on my task list for the day. Back in my day I remember the radio DJ's used to send a message out ....."Turn so you won't burn!".... every half hour of the day. Bottom and top of every hour. So you knew the time and you knew 30 minutes have passed.

I have brand new to me (Samsung Galaxy S6) A spare phone I bought in a deal from AT&T. I know how to create an event and noticed that loaded up my calendar view so it is almost worthless from the number of blocked out time slots. Is there a simple way to do this on this phone or an APP that might be perfect for what I need. I also take a medication to help me focus and other time based events like everyone else does who tries to plan or schedule anything.

Any thoughts or advice appreciated.