AltStore is a legitimate, open-source sideloading tool. It turns your computer into a server to sign the IPA with your own Apple ID.
: QooApp on Android works by allowing users to download and install APK files directly. iOS is a "closed" ecosystem; Apple does not allow third-party apps to install other apps (IPAs) unless the device is jailbroken or using specific sideloading tools. qooapp ipa
