Tehcnically speaking the only qualification is the type of development you need.
However, if you referring to guideline son how to find and assess good outsourcing partners, you should keep in mind:
- speed/quality of communication
- previous work
- payment/delivery terms satisfy your needs

More details can be found here: http://giacomoballi.com/how-to-hire-a-freelancer/

Make sure to look at their previous work, and that what you're building is well within their comfort zone. If you want to build an app or a game that breaks new grounds on UX or visuals you really do need the top talent to get you there.

You're going to want to look for an agency that can work with you on the overall technical strategy and not just the mobile app. Too many times, dev shops will not think about the big picture when building, which can lead to increased development and maintenance costs in the future.

You want to find a shop that can add some good information in the area of user experience. They may not be the main designer for your app, but you want them to be able to think about the user as they are building.

Ultimately, you want to find a partner to help bring your vision to reality, not just some company that will build to your specs. This company may not be the cheapest option, but in the long run, it will pay dividends.

Well, to be true the shops and agencies does have characteristics that people look for. Here are a few characteristics you must keep a watch of:
1. The Company Is Effective at What It Does: This is the most important characteristic to look at if you are looking for the best app development company. This is because good companies are effective at what they do.

2. They Are Employing User-Focused Procedures: Therefore, it makes sense that start-ups would want to partner with a company that has user-focused designers. At this stage, it is important for the start-up to make sure that app Development Company cares deeply about their customers and will prioritize their experience. One of the most famous technique to do this is to download few apps that the company has already created.

3. Creative Enough to Highlight Your App: Creativity is supreme for the best app development company. Nowadays, users download around 8.8 apps every month, so your app must do the outstanding performance. A creative company can assist in making sure this happens. A good company looks at the things from a different perspective.

4. Outstanding Tech Skills: Talented tech skilled workforce plays an important role for mobile app developers. This guarantees that the company will be able to distribute that tech expertise to you and that your app will be as reorganized and bug-free.

5. Possess Determination to Help You Exceed Your Goals: You may have taken the time to create a series of objectives for your company’s app. The app development company your hire needs to be more than only an IT service provider.

6. The Company Must Employ an Agile Development Process: The app development process must be flexible enough to suit your brand and adapt to any alterations your team considers essential down the road.

7. Understanding of Cross-Platform Development: In addition to guaranteeing rationalized production, a company that concentrates on cross-platform development also averts you from having to hire an additional company to provide support to other platforms in the future.
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath