Where can I find a mobile app development partner?

I own a boutique mobile app development firm based in Dallas. I am looking to find a reliable subcontractor to handle overflow. Prefer an agency. My firm is all Xamarin and Azure (Node.js). We recently finished v1 of our framework and platform - details at codeassassins.com. Prefer a partner that can assist with development and mobile ops (Azure). Need to speak with someone that is familiar with process and can assist with a connection. Thank you!