You can buy one app and download it to multiple iOS devices including the iPad, iPhone and iPod Touch, but perhaps more importantly, you can delete any apps that you use infrequently with the knowledge that you can download them again.
Nke a pụtara na ị nwere ike ịzụta ngwa ma budata ya na ọtụtụ ngwaọrụ (gụnyere iPhone na iPod Touch maka ngwa ndị na-akwado ngwaọrụ ndị ahụ), mana ma ọ bụ karịa, ị nwere ike ịnwe onwe gị ịhichapụ ngwa ọ bụla ị maara na ị nwere ike ibudata ha ọzọ.