Using Slider with Raspberry Pi

Can someone point me in the right direction how to use a slider with the Raspberry Pi? Is this possible?

Thanks,
Udo

Okay, my question was a little bit short and unclear. Let me explain:

Everything is running fine so far, I’m able to use Buttons and Value Display in Blynk (on iPhone) to set and read GPIO Pins on the Raspberry Pi (using Python on the Pi).
Now I want to set a value using the Slider in Blynk. As I’m new to all this stuff (Pi, GPIO and so on) it would be very helpful if someone could tell me what in the Blynk App the Digital Pin “~gp18” means. What mode do I have to set the GPIO pin on the Pi?

Any hint is appreciated!
Thanks

a Python library is possibly on the way… check out this thread…

Ya u can use slider for raspberry pi,only GPIO pin18 supports pwm in pi,"~gp18" indicates pwm is possible in this pin.u can check pin diagram of raspberry pi to check for GPIO 18 pin.

Thanks for your replies! That was the missing link, now I think I understand a lot more!