Trigger A transaction received to given address on the IOTA tangle can trigger a rule.
Action A new 0i transaction can be created on the IOTA tangle as a response to a cloud-based trigger

Trigger A webhook (HTTP(s) call can trigger a rule.
Action Totangle can make an HTTP(S) call as a response to a tangle-based transaction trigger

Action An email can be sent as a response to a matching tangle transaction.

Trigger and Action: Use Zapier to connect to over 1,000 cloud-based apps, both as a trigger and as an action. You will need to create a Zapier account (basic ones are free!)

Trigger A new Google Sheets row can trigger a rule
Action A new row can be added to a Google Sheets document as a response to a new transaction on the tangle.

Action A new item (record) can be added to an AWS DynamoDB database as a response to a tangle-based transaction.

Trigger A message received to given MAM channel (stream) on the IOTA tangle can trigger a rule.
Action A new message can be sent to a MAM channel (stream) as a response to a cloud-based trigger

Trigger A page with a form with fields specified by you will be created. Submitting the form will publish your data on the tangle.

Trigger This trigger creates an event when a new file is added to a Google Drive directory.

Action A new document (record) can be added to a Google Cloud Firestore database as a response to a tangle-based transaction.

Action A new document (record) can be added to a MongoDB database as a response to a tangle-based transaction.

Action A new record can be added to a MySQL database as a response to a tangle-based transaction.

Action A new record can be added to a PostgreSQL database as a response to a tangle-based transaction.