As noted in my previous blog, I have been developing apps and games for over 10 years now. I used android studio, visual studio and unity as game engine. Android studio mostly used for android apps and games. Visual studio is for cross platform apps and games. I use unity for games and animations.

Learning curve for all is the same. I used to create sample apps or games and follow along the tutorial. You can also start by learning the IDE then follow along a tutorial. The most important is to understand what each menu or toll is used for.

My process in creating apps follows the principles of good design. Make eye catching designs of the app without interfering with user experience.  You can check my tutorial here.

1. Sketching. I usually start by sketching my app on a paper with pencil. This way I ca always erase parts that are not needed. The sketch usually captures the basic idea of my app. It also captures the main functions of the app. If I am working with client, this is where I usually collect app requirements and required functionalities. I write down then create sketch to guide me. When the sketch is clear and captures the high level operation of the app, I move to UI design.
2. UI design. This is where I spend much of my time. If you get your UI design well, then you spend less time coding. This is where you specify what elements you need on your app. This could be buttons, text boxes, input functionalities, data display elements and other UI elements. Also you design the number of scenes your app will have. I mostly use Adobe XD, Adobe Photoshop and Adobe Illustrator. Adobe XD is used mostly for UI design and prototyping. Adobe Photoshop and Illustrator are for creating UI elements for Adobe XD. I will pick my sketch and draw it in Adobe XD using basic shapes like rectangle, circles and triangles to denote UI elements. After sketch is done, I will either use adobe photoshop or illustrator to draw the specific UI elements. Say if it is button, Adobe photoshop may work better than illustrator depending on visual elements needed. I also use both where I start with photoshop or illustrator and import my design to he other for final touches. I will save and export my design in a folder within my project. I will then import this UI design into adobe XD project and replace my dummy UI elements created earlier. I will also add other small elements that I may not have created earlier. At the end of my design I will have an app that looks like a complete and ready to use app.
3. UX design and prototyping. Still in Adobe XD, I will the link UI elements with intended actions. This could be button click to open new scene or deactivate or activate UI element. This could also be button to save data or open URL link or even exit a scene. I will the play the final prototype and see how all elements interlink. While this may not be operations app, it covers most of the operations needed. 
4. UI elements export. - I will then export my UI elements depending on requirements of IDE an using. Say I am using android studio, I will select android option so that I get all UI elements for android in one export. I will then organize my exports in one folder for ease of access. I will also export scene for reference and also a video of app functionalities as capture in the prototype.
5. Coding in android studio, visual studio or unity. With my UI elements and scene exports, I am ready to code. I will open my IDE in this case android studio. create project and import my UI elements into their specific folders. I will then create layout of the app using my scene reference images. Once everything is ready, I will use the video reference to code my UI elements interactions. This usually takes short time as I already have video for reference. I start with basic interaction then do other complicated integrations like database integration, web services integration.
6. Testing. Once the app is ready, I will do initial test on my android phone or emulator. I will the rectify any glitches and add any other operations that I may have missed during prototype. At the end I will have complete app ready for publishing.
7. Integration with monetization. The final step is to add monetization. I usually use ads and in-app purchase as main monetization methods. I will head back to prototype in Adobe XD and add ads where I feel they fit and are visible. I will also add monetization UI elements where they fit too. I will export and import into my IDE and do the final coding. I will test with real device to make sure what is intended is what client gets. I usually use test ads and in-app purchase items. I will then add my real monetization setting.
8. Final testing. I will do the final testing. This include going over the whole app looking for any bugs. Also checking if monetization is affecting user experience. I will then adjust and export the final files for publishing.
9. Publish on Playstore or other app stores. I start by creating app store account if I don't have. I will make sure to capture my correct data and read terms and conditions. I will also check the rule and conditions of using and uploading store. After I complete, I will then upload my files and any screen shots that may be required. I will use Canva to create additional store elements. I also sometimes use Photoshop or Illustrator to design. Canva usually have ready made templates. I will then wait for publishing to be completed and approved.
10. Review progress and update. After the app is published, I am usually the first one to download and test the production version of my app. This helps in identifying any bug that may have come up when publishing. The next step is now to review my UI design and UX and improve or update. I will then update my app and publish. this is a continuous exercise.