How did you get these users? They signed up on their own through the app or website? With such a small amount of users, you should collect a phone number and just call them.
For figuring out which features a user wants, my old company tried this and had a lot of success. The product was aimed at small businesses and it was a dashboard to help them manage Yelp, Google, Tripadvisor, Foursquare, etc. listings all in one place. So we figured they would want to update their info like phone number or hours, so that should be one tab, and replying to reviews was another big thing so that was another tab. Those were set in stone. But we weren't sure if they wanted a tab for promotions (create a campaign and post it on Google, Yelp, Facebook, Twitter, etc., and customers could redeem with a QR code and there would be analytics), competition (pick N competitors and track their ratings, reviews, etc side by side with yours), social media (see mentions of your business across social platforms and see sentiment analysis over time), or learning (a series of online videos that you could watch, tailored to your business based on different metrics).
So we built out the first two tabs (profile and reviews) but we had dummy tabs for promotions, competition, social media, and learning. Clicking those would popup a form where we would let them ask to be notified when the feature was available, with a freeform text field where they could explain why they wanted or didn't want the feature, or what they expected it to be. It turns out that competition by several orders of magnitude was the most requested feature, and promotions was a non-starter (only a fraction of a percent of users ever clicked on it).
For figuring out which features a user wants, my old company tried this and had a lot of success. The product was aimed at small businesses and it was a dashboard to help them manage Yelp, Google, Tripadvisor, Foursquare, etc. listings all in one place. So we figured they would want to update their info like phone number or hours, so that should be one tab, and replying to reviews was another big thing so that was another tab. Those were set in stone. But we weren't sure if they wanted a tab for promotions (create a campaign and post it on Google, Yelp, Facebook, Twitter, etc., and customers could redeem with a QR code and there would be analytics), competition (pick N competitors and track their ratings, reviews, etc side by side with yours), social media (see mentions of your business across social platforms and see sentiment analysis over time), or learning (a series of online videos that you could watch, tailored to your business based on different metrics).
So we built out the first two tabs (profile and reviews) but we had dummy tabs for promotions, competition, social media, and learning. Clicking those would popup a form where we would let them ask to be notified when the feature was available, with a freeform text field where they could explain why they wanted or didn't want the feature, or what they expected it to be. It turns out that competition by several orders of magnitude was the most requested feature, and promotions was a non-starter (only a fraction of a percent of users ever clicked on it).