You get your first 100 users already so I think you went through the hardest part.
Unless it is all friends, you can analyze those first few users and see common characteristics such as age, gender, location, interests, etc.
These first users are your micro-micro universe and you want to get to know them. Once you found those common traits, you can go out and look for those very similar potential customers and reach out to them.
How?
It depends on your product and service. You can try paid ads via Facebook/Twitter/Instagram/etc, you can try influencers to feature your product, reach out to bloggers in your field, talk to people face to face, etc. etc.
You have to find what works for you and your app.
Make sure that you analyze everything you try. Some things might not work out totally as you expected, but might give you some good lessons how to try next time.
I suggest you check out this list:
http://blog.linkody.com/seo/growth-hacks-list
Thanks for your input.
We are actually trying to get away from this way of working because it does not work any more.
As we have an MVP, we want to get towards some initial traction and if feedback leads us to some direction then take aim in that direction and then if everything goes well then fundraise.
Your type of company has great value early on to get an MVP or MDP but we got to a point where we want in house people to do it who concentrate only on this app.
I appreciate your feedback though and will keep you in mind.
Thank you for your input! I really appreciate it.
If you don't mind asking me, when a professional like yourself chooses a programming language to learn, what are the criteria based on what you make your decision?
Interesting.
The first point resonates with the famous quote made by Bruce Lee.
"I fear not the man who has practiced 10000 kicks once, but I fear the man who has practiced one kick 10000 times."