Tracing and Sending Data Package to Server

Hello. I am quite new to hacking but have cracked a few wifi passwords, router logins and more. Simple stuff.

I am now trying something completely new for me.

I got an app on my android smart phone that is simply a "wall" where you can post messages and then people can up vote or down vote. This app require no login at all. Just start the app and vote. You can only vote once but its easily to get around, just reinstall the app.

I am thinking about sending a lot of "vote up" package to the server and therefore make a post gain many up votes. I used airodump-ng wlan0mon --bssid (my router) -c 3 -w apptest

Then I up voted a post and the "#Data" column increased to one (1).

Now i got a cap file and 2 more files. I open the cap file with wireshark and can see 33 packages the first one is broadcast, then some really small data package and number 4 contains 624 byte of data. I guess there is where the up vote is placed.

The problem now is that i don't know the destination address of the package (what server is it going to?) and also how do I manually send that package to the server to hopefully get another up vote (if it works? but that is not important, i want to learn).

Thanks in advance :)