hello!
i do not have too much experience with this, but afaik, the blynk app needs android or iphone to run. i see 2 possibilities:
- try to run an android simulator on the rpi (it is also possible to install android os directly on the rpi, but then the server will not work)
- depending on what you need to do, if you have java / html skills, you can put together a blynk ui, using blynk api (or see this: Blynk Web Dashboard)