As I can see that Bluetooth controllers cannot be supported by Death Squared, is there any way to play with 4 people on keyboard? It would make it much easier as I have a program the maps button presses on Bluetooth controllers into keyboard presses.
We do support Bluetooth controllers on IOS. Is this what you're referring to?
Some food for thought, any device connected to your Android or iOS phone/tablet/etc. is just a "dumb" input device and should work fine. You're really probably having a different issue. If it's more of a desktop experience you're looking for though, I have tried playing on PC with an android emulator, specifically the "Nox" Player, and I've enjoyed the experience. This method is particularly handy with the Catan game/app which has connectivity issues (regardless of the actual strength and reliability of your connection; it's said I lost connection on a physical Gigabit LAN connection, not even!). Best of luck!