Looking for the perfect project management system?

Question

Project management

Now we use the company " Megaplan ", in many respects a good service with good functionality, but usability is very lame, which causes a continuous negative ... The project is still very damp.
I tried it, as a test , Bitrix24 is an almost ideal system, but the functionality for managing and creating projects and managing them is rotten. There is no possibility to create subprojects
Ideally, find a system with Megaplan functionality and Bitrix24 appearance
System requirements:
- SAAS solution
- Ability to create projects and sub-projects;
- deadlines and timelines
- setting and delegation of tasks
- time tracking
- free for 15-20 users (optional)
- the ability to build reports
- invoicing and payment control
- maintaining a customer base
- providing guest access
- application for iOS / Android (optional)

Answer 1

I think I know what will suit you, but unfortunately I forgot the name, it looks like Bitrix24 and like VKontakte at the same time) very convenient, made by ours,
I’ll write)

Answer 2

Try asking a question on this forum pmexperience.org/ru/forum