You can use some mobile applications to open a .Psd file in iPhone. Photoshop PSD Viewer is an app that you can open .Psd files in iPhone. The free version (Lite) does not have many features and it’s limited to .Psd files. You can buy a different edition with extended features by paying a certain amount of money to reach the suitable edition for different iOS versions. It also can be applied to iPod. You can zoom in with it up to 1000%.
There is a list of apps suitable for opening .Psd file and editing it in iPhone, you can check it:
Best psd files apps for ios (Top 100)
There is another simple way; if you use dropbox you can preview your .Psd file on it.
Another way is to looking in iTunes to find suitable app for opening a .Psd file.