Silicon Valley's Top App and Web Design Company.

1. Organization - Does the company have an office in the U.S or is it just a U.S phone number being answered in India or Ukraine? It's very important to have a U.S based contract to protect your Intellectual property and rights. The best mobile app development companies are in the U.S & understand the market intricately while providing cost benefits by having some of their development teams in cost-optimized locations worldwide.

2. Detail-orientation -They should provide written proposals with very high levels of detail and no fine print. Check if the proposal is meant to win you over with low pricing OR do they provide a high degree of technical knowledge and expertise in the details.

3. Process-driven excellence - The company should provide information about how their process will be, if they will use Project Management tools, Bug trackers, Automated and manual testing, Cloud-based hosting and if their Project Managers and UX experts are based in the U.S.

4. Friendliness and willingness to cooperate - Apps are ideas that take time, effort, discussions, and knowledge to form into a complete product. Check if they will be flexible in accepting change requests as your vision forms over time.

5. A-Z and Low pricing - Ask if their proposal covers everything - Wireframing, Design, Programming, Testing, Source code handover, Launch, and Warranty. No surprises for later.

6. Partnership - The business you ultimately end up deciding on has to be one that pays full attention to your needs through every step of the process of your App development. The company needs to include you in their decisions, and be true partners in your success.