For research, users often look toward archive sites or mobile developer forums like
WhatsApp version 2.18.80 was released for iOS in 2018. An IPA file is the iOS app archive format used to install applications on iPhones and iPads. Users typically look for this specific archive version to install the application on older hardware, such as the iPhone 4s, iPhone 5, or iPhone 5c, which cannot update to modern iOS versions. The Critical Problem: Server-Side Deprecation whatsapp 2.18 80 ipa download
Signal’s old open-source IPAs (v2.40.x) still connect to their servers if you use a registration proxy. For research, users often look toward archive sites
If you have previously downloaded WhatsApp on your Apple ID account in the past, open the App Store on your older device, go to your Purchased tab, and attempt to download WhatsApp from there. If a compatible version exists for your iOS firmware, Apple will prompt you to download the last compatible version automatically. go to your Purchased tab