The cost depends on the needs of your functional city, but the following matters need to be paid attention to when developing an APP, which can be referred to:

What knowledge do you need to master to develop a complete app?

1. Pre-requirement plan and information-you need to make a complete requirement document, function document, flow chart and timetable.

2, interactive design, UI design-design a basically perfect prototype diagram and the interactive design effect of app foundation, and then design a complete UI interface according to these and learn to cut the diagram. Some material pictures that need to be adaptive need patching. Here you also need to know the conversion between px, pt and dp, the conversion of screen density, and the coefficients between them, so that your app can perfectly adapt to devices with different resolutions. Among them, interactive design requires you to know a lot of skills and experience of man-machine operation, master the use of interactive tools such as Axure, and UI design requires you to master Photoshop and Illustrator.

3. To develop app software in ADT and other development environments, you must master the java language and be familiar with the android environment and mechanism.

4. If you are not a stand-alone app and need to use a server, then you have to master the relevant knowledge and development language of WebService.

Words, commonly used are ASP.Net, PHP, JSP, etc.

5. Familiar with and able to develop databases.

6. Some functions need algorithms, which also requires certain professional knowledge, especially the mathematical foundation.

7. Familiar with API interface development, including the ability to develop APIs by yourself and the experience of calling third-party APIs.

8, familiar with TCP/IP, socket and other network protocols and related knowledge.

9. Proficient in App release, real machine debugging skills, certificates, packaging, shelves and other processes. App development is not necessarily suitable for one person, it is too laborious. Unless it is a stand-alone version of a small application or a simple third-party application developed with a ready-made app, a team is still allowed to complete their respective professional fields.