If nostalgia or necessity keeps you on iOS 4.2.1, accept that modern messaging apps will not function. For communication, use SMS, email, or a secondary modern device.
If your goal is messaging on an iOS 4.2.1 device, you have three better options than WhatsApp: Ios 4.2.1 Whatsapp Ipa Download
Seeking an “iOS 4.2.1 WhatsApp IPA” is an exercise in futility and danger.
The last compatible WhatsApp version is over 9 years old and has been shut out of WhatsApp’s servers. Any website claiming to provide a working download is either distributing malware or defrauding users. If nostalgia or necessity keeps you on iOS 4
Even if you successfully download an “iOS 4.2.1 WhatsApp IPA,” you face three insurmountable walls: If your goal is messaging on an iOS 4
If your goal is to keep using an old device for messaging: