Google has stopped the support of SMS reminders for normal Google accounts on June 27th 2015. They are now only available for special Google accounts (e.g. G Suite), please see here:
However if you are using CalenGoo you can use pop-up reminders instead, which have the advantage that they can be snoozed and repeated.
Additionally you can view your upcoming events with a simple swipe down from the top of the screen by using CalenGoo’s Today Widget.
And if you have existing events that have SMS reminders and would like CalenGoo to display pop-up reminders for them without changing all reminders, you can turn "Settings > Reminders > Display pop-up also for SMS reminders" on:
To be able to use SMS reminders you have to configure them in Google Calendar first. Please sign in to Google Calendar:http://calendar.google.comclick the gear icon in the upper right corner and choose “Settings”:Then click “Mobile Setup” and enter your country and phone number. Click “Send Verification Code” to send a verification code by SMS to your phone. Enter the code in the “Verification code” field and click “Finish setup”. Click “Save” afterward:Then you should be able to use SMS reminders in your events.Fixing problems If you don’t get SMS reminders for your events, first ensure that there are really SMS reminders set for your events in Google Calendar. Sign in to Google Calendar, open an event and check if it has a SMS reminder:If there is a SMS reminder configured but you didn’t get a SMS, please try the suggestions here:http://www.google.com/support/calendar/bin/answer.py?hl=en&answer=36589If this doesn’t help, please connect CalenGoo via OAuth2 to Google Calendar by following the instructions under "Authenticating via OAuth2" here: Authentication . Afterward try to create a new event with an SMS reminder again.If it still doesn’t work please report this problem to Google here, because the SMS notifications are sent by Google Calendar, not by CalenGoo. So if you can see the SMS reminders in Google Calendar, but they are not being sent, it is a problem in Google Calendar and only Google can fix it:http://www.google.com/support/calendar/bin/request.py?contact_type=smsIf the SMS reminders don’t work reliably, you can e.g. use “pop-up” reminders which are handled by CalenGoo and can be used even without mobile reception: Reminders