Know What Your Users Want:
Always know your target audience. You must know who you are building the app for and how they might respond to the same. It's important and beneficial to verify that before starting to develop the app.
Make The App Understandable:
Your application should not be a hurdle for the users to understand. Make it a point to include clear instructions wherever you feel it's necessary. Avoid the mistake of assuming that your images will tell the tale. Marry text with your images to make it more comprehensible.
Have A Proper Design Strategy:
Create a well-defined design strategy. Create a storyboard and follow it diligently. Get it approved by your peers and improvise your plan on their suggestions. Also, try and involve potential users in the design phase.
Focus On Developing The Important Components:
Focus on building the core components (functionality) of your app. You can develop the additional components later and release them as plugins which the users can additionally download or purchase.
Make Security Your Top Priority:
Mobile devices are quite vulnerable to various internet threats. You not only need to include the platform's inherent security capabilities but also use stuff like encryption to protect sensitive data. An automatic cloud backup is also important since users don't want to lose their data.