Finding these legacy files can be tricky since many are no longer on the App Store. The most reliable community-driven sources include: The Momentum Store
While fun for nostalgia, be aware that many modern social media apps (YouTube, Discord, Telegram) no longer function on iOS 6 because their underlying APIs have changed, even if you manage to install the original IPA. Cracking and Archiving Old iOS Apps ios 6 ipa files
(if you have the app installed):