Creating a professional networking app is a good idea, but do not know yet how it will likely be and when it will succeed. Because even in case you build the right product, if the timing is not right, it'll be a failure. Instead of creating an app, there are many platforms where you can create a professional network group for youths which is an easy way for youths to connect and take knowledge there. A few ways to create a professional network for youths are:

Create a Facebook Group
Create a LinkedIn Group
Create a Google+ Community

Invite youths to join these groups, then treat the youths as your audience. Create content that gives them professional guidance and they can use to help themselves. Encourage engagement and sharing. Post new job opportunities there. Publicly (in the private group) acknowledge youths in conversations.

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