Tips for Employers to hire a Android Developer

1. Have a good understanding of what you are clear about and what you haven't figured out yet. Scribble down a rough wireframe if possible. Take a picture of it and have it handly. You can give it to the Develop in chat or just attach that when you post the project.
    
2. Does a similar app exists? It doesnt have to be exact same, a similar one would do just fine. Get their links. Developers like to visualise the end product when they start of the idea. Once they know what to make, it is easier for them to form the flow of the application.
    
3. Decide what you need in your MVP: An MVP or a Minimum Viable Product is the most basic version of your idea. It has the features that are core to your idea. All the features that you add to it are the add ons that make your product better and more usable.This decides what screens you will need on the app and how the user would go through them.
    
4. List down the features that you would need in your application. Searches, Image Filters, Image crop tool, Google+/Twitter/Facebook integration, Data Backup etc
    
5. Analytics: Having analytics embedded into your application is the most important and the most overlooked component of an application. Adding analytics tools like Google Analytics gives a very good insight on how your users/customers are using your app. They let you know how long a user spends on a screen, and what are the features the users arent using and a lot more other things that lets you improve you application in further iterations.
    
6. Top freelancers like to read about the idea first before bidding. So along with a Apt Title, write a brief desciption of the idea. Try to get an idea of the cost of application. Talk to some freelancer you know or have worked previously with. Look for freelancers who have good feedback and ratings. Try to get someone with good skills and a little less busy schedule. Do not overlook the rising ones. They may be perfect as they can give all of their working time to you application. Agencies would be best when you have a large application to be developed. They will have a number of people with different skill sets necessary to make you application perfect.
    
7. Do not go for extremely short duration development unless its an urgency.
   For small applications giving the developer 5 days would be really nice. A good developer will be able to bring your idea to life in 2 days. This is the MVP. However, the developer would like to beautify the User Interface and improve the User Experience. The developer will also remove any overlooked bug in the application. 
   
   For medium complexity applications, let the developer have somewhere around 7-21 days time to completely build your applications.
   
   For large applications anywhere between 21 days to 45 days should be sufficient for the developer. This depends a lot on the product that is required. 
    
8. Talk to the bidders, check if they have understood the idea, ask them if they have worked on something similar before. Let them know your requirements completely. Having a list would really help track and discuss each point.
    
9. Finally use your list, to decide the milestones.
   Getting the Minimum Viable Product(MVP) developed first is the best way to go.
   Adding the features should be the next. Adding Google Analytics, Admob/Advertisements, User Interface improvement, Animations can be among them. 
   Then performance(least network usage, caching, battery, faster algorithms etc) improvement. The final milestone should be where you test the applications in Portrait Mode, Landscape mode on multiple screen type and sizes. Test it both on Tablets and Smarphones.
   Do not be conservative with the number of milestones. I would suggest some 5 milestones should be good for both the developers and he employers.
    
10. Be available to talk to the developers at some pre decided time. You can discuss current progress and any clarifications that you or the developer needs. By focusing on the milestones strictly, you can be assured that you would get a great and complete product.

From : freelancer.com