At this time, individual sticker packs or lenses purchased on iOS and Android devices will not be accessible on the other device types.
You should be able to restore purchases made on other devices which use the same store account. For instance, if you make a purchase on your iPad, you should be able to access that purchase on your iPod. This holds true for devices which share the same Google Play store account, or same Amazon account.
If you have upgraded to Path Premium, your Premium subscription benefits will be available on any other devices you have that are running Path version 3.2 or later.