When the stomach makes a sound like croaking of a frog or similar to it (mine just did, it's trying to speak to me), that alert when you are hungry, is there a name for it?
I mean the name for this very sound?
Yes, there is a term for that in English. It's called a growl:
Why is my stomach growling, but I'm not hungry?
I can hear my stomach growling. I'm gonna go grab a bite.
There are actually a number of terms in English that are used to describe abdominal sounds (sometimes called bowel sounds) among which are words like gurgle, grumble, rumble et cetera, but growl is by far the most common. Here's another example straight from Oxford English Living Dictionaries (OELD):
My stomach gurgled.
In medical speak, they use a delightful little word called borborygmi, which is the rumbling or gurgling noise made by the movement of fluid and gas in the intestines. That said, it would be unlikely to be used in casual conversation.
Personally, I would say:
My stomach is rumbling
Or even
My stomach is talking
In addition to a stomach growl, it can be also referred as a stomach moan. Or it could be a stomach drone.
(Droning is making a deep, low-pitched humming noise, discontinuously.)
In my locale of southern England, the term is "my stomach is rumbling".
Other locales use different terms.