One of the major restrictions is limiting the access of the r_fullprofile fields to only explicit LinkedIn partners. This is used by a lot of startups to create a great onboarding UX and minimize user data entry.
While this is a disruption to developers who will now have to adapt their onboarding, more importantly, it's a major setback for millions of LinkedIn users. LinkedIn is heightening their walls and there will no longer be an easy way for LinkedIn users to export their profile data out of LinkedIn and use it for other purposes.
We build an online resume/portfolio creation tool and are offering all our premium plans for free when users signup with LinkedIn until our API access to LinkedIn profiles gets turned off on May 12: https://www.visualcv.com/?ref=freeLinkedIn
Before the LinkedIn API grace period ends, we would love to hear from any more startups that are currently relying on the LinkedIn API for signups and are offering a promo to their services one last time. Please list your startup in the comments below.