In case anyone is still developing for this beautiful phone I just uploaded the SDK I found in my PC. Considering the Yotaphone website is down it might help to someone.
https://mega.nz/#!7nAQVAwb!Y12FXWfJ_yW1S4Z3_66mthi656kzxoOariUFk8HX-jA
https://mega.nz/#!7nAQVAwb!Y12FXWfJ_yW1S4Z3_66mthi656kzxoOariUFk8HX-jA