WhatsApp Delta is a modified version of the popular messaging app. It allows you to use the app without being in the same group as other users. However, before you can use it, you have to download the APK file from a third party website. Be sure to back up your existing chats before installing the modified app. Also, it is important to note that installing a modified version of WhatsApp is illegal and is not recommended by Google. In addition, Google may temporarily block users who install modified versions of their service.