Hi
First of all, well done for building a business - getting users and downloads - this isn't an easy thing to do.
The best option (based on what you mentioned) for selling your app, would be to use one of the following websites:
1. https://www.businessesforsale.com/search/websites-for-sale
2. https://www.trustiu.com/en/websites-for-sale
3. https://flippa.com/apps
4. https://www.sellmyapp.com/
If you want someone to take it over for equity, you could use the above websites, or look for a co-founder - using the below websites:
1. www.founderdating.com
2. www.cofounderslab.com
3. http://www.founders-nation.com
4. www.founder2be.com
Whether it's a buyer or co-founder, if the value of the transactions is about $2,500 USD, then remember to sign a professional agreement and execute the transaction via the right stages (I'm happy to help with this if you need).

I've successfully helped over 350 entrepreneurs, startups and businesses, and I would be happy to help you. After scheduling a call, please send me some background information so that I can prepare in advance - thus giving you maximum value for your money. Take a look at the great reviews I’ve received: https://clarity.fm/assafben-david