I was not able to tail -f several log streams from different applications, interleaving them with some blank lines.
So here it is:
interleave "heroku logs -t .." "heroku logs -t .."
Add this line to your application's Gemfile:
gem 'interleave'
And then execute:
$ interleave "app 1 output stream" "app 2 output stream"
Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/interleave.
The gem is available as open source under the terms of the MIT License.