Many. First off all: define your needs. Main differentiation is whether the device can 'speak' ETTL or not. ETTL-capable devices costs more, the other ones are quite cheap. Check the Mass Sales and the Virtual Shops here.
Those are just brands. Not all of the models offered by those brands do wireless E-TTL.
For Pixel, only King and Knight series triggers offer E-TTL.
For Phottix, only the new Odin series offer E-TTL.
For Pocketwizard, TTFlex series offer E-TTL.
For Yongnuo, don't remember seeing anything that is E-TTL.
Those are just brands. Not all of the models offered by those brands do wireless E-TTL.
For Pixel, only King and Knight series triggers offer E-TTL.
For Phottix, only the new Odin series offer E-TTL.
For Pocketwizard, TTFlex series offer E-TTL.
For Yongnuo, don't remember seeing anything that is E-TTL.
do u mean, when my flash do not have E-TTL function, once i connect to the wireless trigger, i will have E-TTL function?
if so, i think i can also get manual flash for this function liao...
Sorry to burst your illusion ... answer is NO.
ETTL requires electronics in the flash and the programming to 'understand' and to communicate with the camera. The lingo is specific to the brand. Also, as result of this communication the flash is able to receive signals about the required flash output power and adjust itself accordingly. Manual flashes can only be controlled using the buttons on the back.