Q: Is it safe to download WhatsApp IPA on iOS 4.2.1? A: While it's possible, it comes with certain security risks.
: When a legacy app launches, it attempts to connect to WhatsApp's modern servers using outdated encryption protocols. The servers instantly reject the connection.
For an iPhone 3GS on iOS 4.2.1, iMessage works perfectly (with an Apple ID). If your contacts also use Apple devices, this is your best native solution.
If you are looking to download a WhatsApp IPA for iOS 4.2.1 to use on an iPhone 3G or original iPad today, the short verdict is:
