It's app for Android that can send apps traffic via your proxy. Your device need to be rooted.
You can use this with Burp Suite proxy. Note: Use invisible proxy option in proxy listener options.
App using iptables routing like this:
iptables -t nat -A OUTPUT -p tcp --dport <dport> -j DNAT --to-destination <proxy address>:<proxy port>
Using guide can be found here.
