How to synchronize the frame-rate on different devices?
The reason for so few answers might be that the question is a bit unclear.
Do you need to have synchronous GAMEPLAY or what?
And similar topics have been debated before, so perhaps you should have a quick look through the first two pages of threads in this category, check if what you want to do is already covered.
A lock step game synchronizes frame rate. It does it by waiting for everyone else’s input to arrive on a frame by frame basis before resolving and rendering the frame.
Its also a TERRIBLE model for anything other then LAN play. And even in LAN play you have just forced everyone to run at the performance of the worst player.
In general you don’t want to tie frame rates together in this way if you can at all avoifd it.