Even if you're applying for an entry-level mobile developer position, you should have already developed some mobile applications, either for commercial, educational, or personal use. Organizations will expect you to have previous experience developing applications and provide them with either URLs or downloadable applications they can view. As a mobile application developer, you should begin developing your portfolio of applications as soon as possible, preferably during your training or education. Producing the portfolio on demand is essential to succeeding in the job search process and responding to questions like this.