Unfortunately, Blink shut down official integration when they were purchased by Amazon. IFTTT offered applets to arm/disarm modules as well as send motion events. See @RBoy 's original post above. IFTTT has recently decided to go to a pay for service model, so depending on the number of applets, that isn’t an option for a lot of us. IFTTT has also had it’s issues, significant lag with motion detection for example.
I recently discovered an open API of blink, which can be used for arming/disarming, reducing my reliance on IFTTT. Post above. API calls are done via webCore unfortunately that too has its limitations, one way communication ST to blink.
Regardless of the method you use, it will require the creation of virtual switches/motion devices.