Historically, ihappymod.com existed. However, as of recent years, that domain often redirects to secondary sites or is parked. Do not trust the first ".com" result on Google. Many are ad-filled clones designed to infect your PC.
A tool that patches apps on your device instead of downloading pre-modded APKs. Requires root for best results but works non-root with virtual spaces.
A: This usually means your Android version is too old (below Android 5.0 Lollipop) or the APK file was corrupted during download. Try re-downloading from the official .net link.