So you are thinking of developing a mobile app, but you are not quite sure of where to go or how to do it. Don't worry, we got you covered. Please let me introduce myself. My name is Juan. I am part of Hamro Dev, a remote web and mobile development company with bases in Italy, Spain, France, United Kingdom, Nepal and Mexico for the time being). I've been working in the web and mobile app development for quite some time now, which is why I decided to start this exciting blog project.
I want to share with you, based on my own experience, the key tips that will lead you to develop successful mobile or web application. Having a great idea is the starting point to a successful app, but before you go straight into detailing the app, you must clearly define the purpose and mission of your app.

1 - Define your project properly
Each person has its own mindset and viewpoint. Before approaching any development team that might assist you in the making of the project, make sure that you define your project properly. This means sitting down, thinking and taking notes of your ideas so you can talk them through with whichever team you end up choosing. This is the first initial discovery phase and it is the most crucial part of your development project. I cannot stress this enough. By the end of this point, and before you dive into proper core development, make sure that you have elaborated a document (word, pdf, powerpoint) where you explain everything that your app must do and how it must do it with as much detail as possible. Use mockups and sketches, include screenshots of similar projects with similar ideas so that the developers know exactly what you are expecting them to deliver.
Start Sketching and designing.
This phase is so crucial and wide that sometimes it requires an external consultancy. If you find it difficult defining your project, ask for help, pay for it if necessary. It is crucial for the correct ending of your project. Most of the apps that I've seen fail have been because of a lack of a proper specification.
Having a first rough sketch of your app is very helpful for everyone on your team to fully understand the mission. These sketches should be used as a reference for the next phase of the development project. (you can read more about this here)

2 - Ask around
With the document ready, google or use Facebook to find out about development teams that could be interested in developing your idea. Ask more than one budget and listen to what each of them has to say about your project. They have developed many more apps than you have and you can use their experience to further enhance your app, make better descriptions of your project and implement new ideas that you might have not thought about.
3 - Make time for your project
Another reason that I've seen projects fail is that people expect their apps to just work by themselves. As you plan for how to develop an app, you need to make time to adapt the business model that comes with it. When you define functionalities in your app, also think in who is going to attend customers if problems arise, and how many people you are going to need for the business to handle itself. It might sound very straightforward, but you'd be surprised.
4 - If you don't understand about technologies make space for new knowledge
It is never late to start learning. If you are going to go into web development then you must learn how to use tools such as Jira, Trello, Invision... Learn how to collaborate with your development team so they can keep you posted of all the process development. Communication is essential during the development.
5 - Have a good communication flow with your development team
Most of the projects I've managed have had delays because of the client not being able to deliver the necessary information or make the right decisions in time. Your development team will probably have assigned more projects to develop other than yours. It is important for you to maintain and keep a good communication workflow with them. Make sure they have all of the information they will require beforehand. If you are going to publish an app to the play store or app store, then make sure that the dev team has access to the google and apple accounts beforehand. You would be surprised of how many delays these small things create. If a decision is to be made, make sure you take your time and properly inform your development team as soon as possible.

6 - Study your user app behavior
How are your users interacting with your app? Are they understanding how it works? Are all the features working the way you want them to work? Figuring out these things is a key factor as to how to work around your next steps in the development. Many clients come to me with one idea in mind, but after testing and iterating they realize that idea is not really what they initially had in mind. They change key features or remove features they thought would be very important at the beginning of the development. If this is your case, don't worry. Not only it is normal, but also very necessary for the healthy development of an app.
7 - KISS (Keep it simple stupid)
As you design and advance in the process of your user interface design, keep in mind that users want things as easy as possible. This means them having to press the screen as little as possible. Make your app as intuitive to use as possible. Flat simple interfaces elegantly allow your user base to learn how to use your app quickly. If your app requires a manual or a user guide then you are doing it wrong.
7 - Test, iterate, test
Testing is one of the most important parts of any software project. In Spain, we talk about marrying an idea when one of our features we like so much that we try to push it even if it doesn't properly work in testing environments. This is a bad situation. Sometimes we put so much effort into an idea that our opinion becomes biased. I've seen this happen in many many projects. CEOs and CFOs pouring money into adwords and facebook ads to an idea that just didn't quite make the cut. Never stop testing, don't get married to any of the features of your app. Market growth implies many changes in your app design and overall user experience.