One of the most powerful ways we've found to take small group attendance is using a text keyword which then creates an attendance record in the group.  With the workflow import feature in Rock v9+ this recipe is actually quite simple and straightforward.

Step 1: Import the workflow
In the related files below, download the JSON file which is an export of the workflow.  Import it into Rock by using the Power Tools -> Workflow Import/Export feature.

Step 2: Update the SMS Response Number
Once the workflow is imported, you will need to update an attribute for the phone number used for sending a response in situations where we have to gather the person's information.  This is the 3rd activity in the workflow and the action is named "Send the SMS Response":
Screenshot_2019-11-21 Workflow Configuration Rock RMS.png

Step 3: Create a Public Web Page for Workflow Entry
In situations where we don't have a matching person OR where we have more than 1 person matching a phone number, the workflow will respond with a link to allow a person to enter their information which will be used to match the person who will be checked in.  Once the page is created, you'll need to add the workflow entry block on the page and set the workflow attribute on it:
Screenshot_2019-11-21 Text Check In Southeast Christian Church(1).png

Then set the page route to "TextCheckIn/{WorkflowGuid}"
Screenshot_2019-11-21 Text Check In Southeast Christian Church.png

Step 4: Create the Text-to-Workflow Defined Type
Simply add a new defined value for each group you want to check into by going to "General Settings -> Defined Types -> Text To Workflow" and clicking the "+" button.  The keyword field will need to be unique for each group.  Then in the Workflow Attributes section you'll need to set the Group attribute by entering the GUID of the small group:
Screenshot_2019-11-21 Defined Type Detail Rock RMS.png
Note: If you don't know how to fetch the GUID of the group but you have the ID you can use the following SQL in "Power Tools -> SQL Command" to fetch it:

SELECT GUID FROM [Group] WHERE ID = [Your Group ID Here]

Step 5:
Start checking people in!  You will want to test this fairly well to make sure the attendance records are being created on the group and everything is working as desired.