I am creating a map for disaster management -currently Puerto Rico and we need to make it accessible to a team of 100's of people but not make it public. I know we can use the Organisation Tab and add users but this only allows about 20.
Can we just have the web app to ask for a generic login/password that we share with those that need access or ideally link to a social media account that we assign access to?
I am new to ArcGIS Online.
Since your project is for a humanitarian purpose, you could try Esri's Disaster Response Program to see if they can provide additional ArcGIS Online accounts for your project.
They seem to have a good track record of assisting in disaster recovery situations. See http://www.esri.com/services/disaster-response/hurricanes for some "ready to use apps" which may also assist.
Because ESRI sells by the seat you are essentially asking how to circumvent there pricing model. The only way you can do what you are asking without purchasing more organizational seats is to allow / be ok with username and password sharing.
You could embed a public map in a secure site but it's still public and searchable on agol. It's a commercial product and paying for named users is there pricing model no way around it.
I guess if you really wanted to hack your way around it you could embed a secure agol site in your site and use you own authentication and have it pass a Single username and password to the agol map that your users would not see. This seems like a lot of work and unethical, mine as well just use an open source portal solution at this point or buy the seats that esri wants you to purchase for using it's product at an enterprise scale.
