There is some provision for a desktop based control - Blynk Web Dashboard
I believe it utilises the Blynk HTTP RESTful API - http://docs.blynkapi.apiary.io/#
And there may be more that I am unfamiliar of. You can also use Non-Blynk methods and do serial prints to the IDE monitor or other terminal programs via USB or TTL-USB, perhaps even serial over Bluetooth links (from hardware device to PC).