On June 26, 2017 today released the next Tantei Jinguji Saburo (Jack Hunter) detective game in Japan the Tantei Jinguji Saburo Oldies. This game is available on iOS and Android for 480 Yen (with tax) / chapter but the basic application is available for free which includes the Chapter 1 too.
At the moment you can buy chapter from 3 different games (Kito no Yoru, Akenai Yoru ni and Naki Ko no Shouzou) for the game but Arc System Works going to release more in the near future. If you like the Visual Novel style detective game series you have to give a try for this game. You can watch the official promotion video above.