Updating Apps and the Operating System Without Breaking Anything

Last September, a member of my class came in with a phone that had stopped working with her bank. She'd applied an iOS update overnight; the bank app crashed the next morning when she tried to open it. She thought the bank had been hacked. The bank thought the phone had been hacked. Both of them were wrong. The update had moved a setting the bank app needed, and the app hadn't yet been updated itself to handle the new version of iOS. Two days later the bank released an update, and everything worked again.

That kind of mismatch is rare but real. Here is how I think about updates, refined over thirty-two years of doing this for a living and three more years of doing it for free at the church.

Two kinds of updates, and they're different

App updates are small. They fix bugs, add features, patch security holes. They install in seconds, almost always work, and almost never break anything. You should apply them whenever they're offered.

Operating-system updates are bigger. They're labeled with version numbers like "iOS 18.5" or "Android 15." They install in 10 to 30 minutes, restart the phone, and occasionally cause apps to behave oddly for a day or two until the app makers catch up.

The two require different attitudes. Eager for the first; patient for the second.

App updates: just let them happen

Both phones let you turn on automatic app updates. I recommend doing this. Apps will update overnight when the phone is on a charger and Wi-Fi, and you'll wake up to slightly newer versions of everything.

iPhone: Settings → App Store → App Updates → on.

Android: open Play Store → tap your profile photo → Settings → Network preferences → Auto-update apps → "Over Wi-Fi only."

The reason I add "Over Wi-Fi only": some app updates are several hundred megabytes, and you don't want those eating into your cellular data allowance.

If you'd rather review each update before it installs, you can leave automatic updates off and instead check the App Store or Play Store once a week for available updates. About the same outcome with more involvement.

Operating system updates: wait a week

This is the rule I'd want every senior to know. When iOS or Android announces a major update — usually in September or October each year — wait at least seven days before installing it. Watch for news about whether the update is causing problems. The first week of a major operating-system release is when issues like the bank-app crash above tend to surface.

After a week, if everything seems quiet, install the update. By then any app makers whose apps had compatibility issues will likely have shipped a fix.

For smaller "point" updates (iOS 18.5.1, Android 15.0.2) — these are usually security patches. Install promptly.

For the big "dot zero" updates (iOS 19.0, Android 16.0) — wait a week.

How to actually apply an OS update

Don't do it in the middle of the day when you need the phone for an appointment. Don't do it five minutes before bed when you want to set an alarm. Updates take 10 to 30 minutes, during which the phone is unusable, and the very last step before the update completes is a restart that can take five minutes on its own.

The right time is evening, after the phone's last expected use. Plug it into the charger. Make sure you're on Wi-Fi (not cellular). Start the update. Go do something else for half an hour. Come back; the phone will either be done or close to done.

If the update fails partway through — which happens occasionally, usually because the phone lost Wi-Fi or ran out of storage — restart the phone by holding the side button until it asks. Try the update again. It almost always succeeds on the second try.

The two things to check before an OS update

Storage. The phone needs about five to ten gigabytes of free space to download and install a major update. If the phone is nearly full, the update will fail. Settings → General → iPhone Storage (iPhone) or Settings → Storage (Android) shows what's available. Delete a few old photos or apps to clear room if you need to.

Backup. If you've been backing up to iCloud or Google (which you should be — covered in our setup guide), a fresh backup before a major update means that if something does go wrong, you can restore. The phone usually backs up overnight automatically; you can also force one immediately. Settings → [your name] → iCloud → iCloud Backup → Back Up Now (iPhone).

What to do if an app stops working after an update

This is the situation my class member found herself in last September. The remedy, in order:

First, force-close the app and reopen it. On iPhone, swipe up from the bottom of the screen and pause, then swipe the app's window up off the screen. Tap the app icon to reopen. On Android, same idea — recent-apps view, swipe the app away, tap to reopen.

Second, restart the phone entirely. Hold the side button until you can power it off. Wait fifteen seconds. Turn it back on. Open the app. Many post-update glitches resolve at this step.

Third, check whether the app itself has an update available. Open the App Store or Play Store, search the app's name, and look for an "Update" button. If there is one, the app maker has noticed the problem and shipped a fix.

Fourth, delete and reinstall the app. You don't lose your account data — that lives on the company's servers, not in the app on your phone. Sign back in.

Fifth, contact the app maker's support if all of that fails. Don't search the internet for fixes — many of the top results for "X app not working after iOS update" are scam pages.

The thing I no longer worry about

Years ago I would tell people to wait six months before installing a major operating-system update. The compatibility issues were that frequent. Apple and Google have both genuinely improved in the last few years. A week is enough for most of the issues to surface. Beyond that the security risks of running an out-of-date OS outweigh the small chance of an app glitch.

The class member with the bank app trouble? She updated her iPhone again the next September, after a one-week wait. Her bank app worked the morning after. She has not refused to update since.

Most software in the world is not going to be broken by your update. Your bank is not going to take your money out of spite. The phone you bought is meant to be improved over time by its manufacturer, and ignoring those improvements is, in the long run, less safe than embracing them with a small amount of patience.

Written by Robert Sandoval. Last verified 19 June 2026.