What are the task trackers + messengers for a small team?

Question

Work organization

Hello.
There is a task to organize work on a project for a distributed team of 3-8 people.
You need a tracker with a minimum set of functions: task setting, attachments, status, comments.
And a messenger, convenient for teamwork, with a good client for the phone (iOS).
It would be great if there is a free solution, or not very expensive.

Answer 1

There's an answer. Thank you all: habrahabr.ru/post/223709

Answer 2

did not think about Bitrix 24?