Doom Strike by Dragonest for Android/iOS (iPhone/iPad).
Plunder NPC cities on the world map(e.g. Holy Hanseatic League or Council of Prometheus) and there is a chance to get techs.
Attack non-ally players’ cities on the world map and there is a chance to get techs.
Purchase techs in Alliance Store. It is required that: The members in your alliance meet minimum donation requirement for the tech you want to buy