I think if the project is genuinely mining through the apps then they're mostly going to dry out the cell and power of that phone. If an actual project uses the CPU of the phone then it is going to affect its performance. But, if that is just a simulation then these projects are not going to hurt your phone unless they do some back job through the hardware of the phone. That is kinda too deep but that's possible so, be careful with the apps these projects you download because you'll never know if they're going to drain your CPU an other components.