Memo to Me - Online email & SMS reminder service.
ifttt - IFTTT puts the internet to work for you. Create simple connections between the products you use every day.
Simply Remind Me - Free email and text reminder service so you don't forget the important things in life!
Zapier - Connect the apps you use everyday to automate your work and be more productive. 1000+ apps and easy integrations - get started in minutes.
FollowUpThen - The simplest way to schedule an email reminder
n8n.io - Free and open fair-code licensed node based Workflow Automation Tool. Easily automate tasks across different services.