Write or use source code for AndroidL2TP/IPsec VPN Protocol application to work on fire os

Im looking for a simple basic vpn application where user put's user name and password for vpn in all other settings are hard coded. I dont mind if you use source code for this project DEVICES Must work on android and fireos ##################################### there is already a working application coded by a 3rdparty company that works so i want something the same - [login to view URL] ###################################### CLIENT SIDE Client installs app enters username and password and vpn is connected