Sindhudesh
The first who proposed this was  Ghulam Murtaza Syed (1904-1995). At first, Syed liked the idea of Pakistan, a state for all Muslims. Later he joined the opposition; he thought that the Pakistani government betrayed the inhabitants of Sindh. In 1971, there was a war, that ended with East Pakistan becoming independent (and calling itself Bangladesh). After that war, Syed put forward his proposal of an independent Sindh, which he called Sindhudesh. Even though the movement exists, it wasn't able to gather a huge following. This is partly due to how the state of Pakistan is organised.