Speak on/by/on the Skype

[ratóncolorao]

Hello,

I would like to know which of the following sentences you would choose as the correct one:

I speak on the Skype every day.

I speak on Skype every day.

I speak by Skype every day.

Thank you very much.

[bhaisahab]

Hello,

I would like to know which of the following sentences you would choose as the correct one:

I speak on the Skype every day.

I speak on Skype every day.

I speak by Skype every day.

Thank you very much.

I use Skype every day.

[SoothingDave]

If I didn't use "Skype" as a verb, or as bhai has above, I would say "I talked to her on Skype."