Dear HN, iOS devices do not have a 1 year lifespan. You need to cater for 2 - and realisticly 4. Plenty of people upgrade their phones annually. But that phone gets sold on ebay or passed to the next member in the family.

// Your target audience for an app may be bleeding edge -- but for a lot of situations: "only a fraction of your audience will have old devices" is not right.