If you type Digital Pill Timer into Google you will see loads , mainly on Amazon and EBay.
My husband has a Lifemax pill holder that holds a day's supply ( 14 tabs) and hangs on a cord round his neck.
You set it to ring for example after 2 hours and then get your pills out and reset it for 2 hours again.
It is small, reliable and worn under his jumper.
? Worth a look.