The best replacement for iterm2 is terminal.

The best alternatives to iterm2 are rated as following:
★★★★★  terminal
★★★★  terminal mac
★★★  tmux
★★★  totalterminal
★  zsh
★  securecrt
  visor

Your alternative for iterm2 is not listed? Suggest!
Speaking about iterm2, one probably shouldn't forget about tmux.

Other search terms related to iterm2 and their ratings are:
★★★★★ tmux
You have in mind a companion for iterm2 and it is not yet here? Propose!



Google Trends

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iterm2
terminal
terminal mac