Q: I've been using an app called "Minimalist To Do List" on my iPhone 6 for about four years and have put a lot of pretty valuable information in it. When I recently updated the phone to the new iOS 11 operating system, I discovered I had a few apps, including that one, that wouldn't work. Instead, I got a message that said that Minimalist To Do List "may slow down your iPhone. The developer of this app needs to update it to improve its compatibility." But I haven't been able to contact the developer, and I got no help from Apple or Verizon Wireless. Is there a way I can get my data back?
Chris Hoehn, Marysville, Ohio
A: No, the data is gone because your app won't run on iOS 11.
You and others who upgraded their phones to the newest iPhone operating system have permanently lost the use of some older iPhone apps that use what's called "32-bit computer architecture." They won't run on iOS 11 and Apple won't let you to "downgrade" your phone to an older version of iOS.
Unless you follow Apple's announcements closely, you could easily have missed its disclosure earlier this year that iOS 11 would abandon the use of 32-bit apps. But the impact was significant. When iOS 11 was introduced in September, the Apple App Store still contained more than 180,000 apps that were incompatible with it, including "Minimalist To Do List."
Minimalist" was created for iOS 4 and was last updated in 2012. The most recent information on its developer's website is two years old, which probably means the app will never be updated.
Technology and marketing influence Apple's changes.
Prior to the iPhone 5s, the iPhone used a 32-bit processor chip that stored data using memory addresses that were 32 characters. But it became clear that for iPhones to compute faster and store more data, the 32-bit processor chips and their software had to be replaced by 64-bit versions. When a 64-bit processor chip is paired with 64-bit software (memory addresses are 64 characters), it can run twice as fast and use 256 times more memory than a 32-bit chip.
As a result, Apple in 2013 began putting 64-bit chips in the iPhone 5s and its successors. But, to avoid making the thousands of existing 32-bit apps in the App Store instantly obsolete, Apple "grandfathered them in" by making its future operating systems run both old 32-bit and new 64-bit apps.
But Apple clearly didn't want to support the aging 32-bit technology forever and began urging developers to rewrite their apps in 64-bit architecture. As a result, most of the App Store's 2.2 million apps are now 64-bit software. That made it safe for Apple to change its marketing strategy and end the use of old 32-bit apps with the introduction of iOS 11.
Apple has not yet removed all of the remaining 32-bit apps from its App Store. As of last week, the "Minimalist To Do List" was still there. But users of iOS 11 need not worry that they will get an unworkable app. The App store only shows you apps that will work on your version of iOS.
Those who haven't upgraded to iOS 11 yet can check to see which of their apps will be affected and choose not to upgrade if a much-loved app will no longer work. Go to Settings, choose General, select About and then click Applications.
E-mail tech questions to email@example.com. Include name, city and telephone number.