You can multiply using chests with two devices.

If you are using two devices and you are both looking in the same chest and you touch the same idem at the same time, you both get that idem in your inventory. You can multiply this way.

I thought that only one device would get the idem.

*What actually happened was both devices got the devices.

Steps to Reproduce:
1. Get two devices on the same world at same time.
2. Both look at the same chest
3. Tap whatever idem that is in that chest that you want to use (It does not matter) at the same time.
4. Both the devices get the idem that you tapped.
5. An unfair way to get endless of everything.