Finding the right co-founder is like a marriage. It's not a good idea to jump to bed with whoever comes along. Most investors and accelerators bet for the team that have a previous relationship before.

The best option is definitely to spend time in the geographical area you'd like your co-founder to be and start going to startup meetups and events. It takes time, but it's worth it when you find the right partner.

Although I don't recommend it, here are some websites that can match you with co-founders:

https://www.founder2be.com
https://www.cofounderslab.com
http://www.founders-nation.com
http://founderdating.com