I've just had a look at the app. You have less than 500 installs so you're note going to make any money from advertising. You're also probably not going to make money from selling anything - people who use your app use it because they they want help others and are not charging for it. They are doing it for free because they feel good about it and they don't want to be charged for that either. So freemium model wont' work, limited period promotion model wont work, usage model won't work, in app purchases model (think Zynga/Candy Crush model) won't work and Upsell/Cross-sell model won't work for that reason specifically.
You might have to consider these models:
- A donations model - People make donations to the developer of the app because they feel good about it or they love the app. Wikipedia has used this model successfully. Another way of doing this would be that users (who feel good about helping) make donations to other users who need monetary assistance. And you can keep a transaction fee. Speaking of donations too, you may want let people use crypto currencies such as Bitcoin and Dogecoin to make these donations. The biggest uses of these currencies today are donations/charitable causes. I guess this is because sending money using these currencies have close to zero transaction fees and they allow micropayments - think payments which are less than $1 - you cant make micropayments with VISA or MasterCard.
- You can use a sponsorship model where you use a sponsor to finance you. Let me give an example: There is an organisation called Capital Area Food Bank which distributes food stamps and food hampers in Austin, Texas. A lot of these distributors are volunteers. If you can get that organisation to be one of your users (users who are looking for helpers that is), you can ask them to be a sponsor - lets face it, they have some money and can afford to sponsor a few thousands if they find the app useful. Those are my two satoshis