There are many mobile app development services available in USA and Canada. Here are a few options:

1. Fueled - Fueled is a full-service mobile app development company based in New York City. They offer custom mobile app development services for iOS and Android platforms.

2. iTechnoLabs - iTechnoLabs is a mobile app development company based in Sheridan. They specialize in designing and developing mobile apps for startups, entrepreneurs, and businesses.

3. Blue Label Labs - Blue Label Labs is a mobile app development company with offices in New York City, Seattle, and San Francisco. They offer mobile app design and development services for iOS and Android platforms.

4. Konstant Infosolutions - Konstant Infosolutions is a mobile app development company with offices in USA and Canada. They provide custom mobile app development services for businesses of all sizes.

5. MindSea - MindSea is a mobile app development company based in Canada. They specialize in creating mobile apps for iOS and Android platforms.

6. Chop Dawg - Chop Dawg is a mobile app development company based in Philadelphia. They provide custom mobile app development services for startups and entrepreneurs.

These are just a few examples of the many mobile app development services available in USA and Canada. When choosing a mobile app development company, it's important to consider factors such as experience, expertise, and cost to build mobile applications to ensure that you find the right partner for your needs.