How much MasterNode I can started on 1 ip?
1
A really easy and awesome solution is this service: https://www.hostmns.net/
He guides you through the process but basically how it works is you download desire wallet onto your pc and wait for it to sync, buy 1001 desire and send it to your wallet. Then you create your password and setup the masternode. After getting your info, he sends you an ip address to put in. You start the masternode on your computer but once you've got it running, its also running on the vps. Now you can close your wallet, turn off your computer, etc and its smooth as silk.
You can download masternode app onto your phone from google play and then get notifications each time you get paid.