Here's a quiet assumption built into every family's phone setup: apps come from the App Store or Google Play. Age ratings, content review, the "ask to buy" approval that pings your phone — all of it lives inside the official store.
Sideloading is installing apps from anywhere else. On Android, stores like APKPure and APKMirror hand out installable app files directly. On iPhone, tools like AltStore and Scarlet install apps Apple never approved — and Cydia, if you ever see it, means the phone has been jailbroken, its built-in protections deliberately removed.
Why kids sideload
Usually for reasons that sound harmless when they say them out loud: a game not available in their country, a "modded" version of a game with unlocked features, an app that was removed from the store, or simply getting a paid app free. Sideloading spreads through friend groups as a clever trick, not a transgression.
The trouble is what comes with it. Modified apps from third-party stores carry real malware and account-theft risk — those "free unlocked" versions are free for a reason. And more to the point for parents: anything can be installed this way. Every app category on this site — vault apps, dating apps, anonymous chat — can arrive through a side door with no rating, no review, and no approval prompt to your phone.
The core signal: a sideloading store on the phone matters more than any single app it installed. It means the official store — and everything you've configured inside it — is no longer the whole story of what's on that device.
What Device Nanny shows you
Alt stores and sideloaded apps don't announce themselves, and iOS tools like AltStore are specifically designed to fly under the radar. Device Nanny reads the phone's actual installed list — everything present on the device, however it arrived — and flags sideloading tools by name. If Cydia is on an iPhone, you'll know the phone is jailbroken. If APKPure is on an Android, you'll know Play Store controls aren't the full picture.
If you find one, ask what it was for
Start with the honest question: "What did you install with this?" The answer is very often a game mod — which gives you a real, non-dramatic opening to talk about the malware risk to their accounts and photos, not just your rules. Kids respond better to "this can steal your Roblox account" than to "because I said so." Then decide together whether the side door stays open.