Hey @cuongdn1102, My one friend recently did a Udemy course and in the course is a list of projects that one can do. We’re doing one right now called “Find My Pet”. This is great as one can engage with the community and you need to rely on a lot of different techniques to get what you are looking for. I’ll try to find the list…
Alternatively, depending on your backgroud, what I like to do is to review apps that I regularly use. For instance I used to use Yousician (musical app) on a daily basis and I had quite a lot of frustrations with it. From the navigation & task flow to the button proportions and repeat errors I made due to UI. Then one can do an “App Review” and put down your recommendations. You could even go so far as to reach out to the communities on Facebook (very active community in Yousician’s case) to find out if your frustrations are consistent with others. This way you can do a lot of reviews and projects that doesn’t take TOO MUCH of your time, yet have exposure to research, data, design and even potentially interactive prototype testing with community members.
I would however suggest that you state somewhere in your case study that it’s fictional or research purpose.
I hope this helps you