whatsapp online tracker

Hi,
I would like to build a WhatsApp online status tracker application website, android app and iOS (this one can be done later if out of budget) similar to chatwatch, waradar, whatztrack…
Here is what’s needed:
1- UI Design
2- Membership system
3-Reseller system (reseller panel)
4- user can track multiple users depending on the membership plan
5-Detailed reports: online history, compare two contacts status (chat probability)
6-Notification system via app or telegram bot
7-Free trial
Further details will be discussed via pm.