This is a very interesting idea with a lot of potential! My only question for you is how you plan on overseeing the work of the students? I know that when I was in high school, I definitely was not always doing work when I told my parents or teachers I was. By pushing this work onto students phones, I feel that it is even easier to get distracted, and more important to implement proper oversight. Additionally, in order to further support the educational use of the base school, have you considered adding team-based lessons to the app to encourage student collaboration? In my experience, I have learned the most while working in teams and I think it is a vital part of the learning process.
Your idea is absolutely correct in that networking is a huge part of a students professional development and future career path. My question for you is how are you going to attract alumni to be mentors in this program? I know that many alumni enjoy staying involved with their universities, but what would they get out of being a mentor for this program? Additionally, to further build the network for students, I think it would be beneficial to students if you were to also expose them the research and ideas of their fellow students/mentors. This could be done by having students present their ideas to others in the program, and would allow both mentors and students to access a more diverse audience who could contribute ideas.
I love your idea and how passionate you are about focusing individual attention on a neglected group of the college market! My only question for you is what exactly the "in-person support" entails. Since the students you are focusing on are also working, I'm sure they are very busy and would need to move their schedule around to accommodate this support. To that end, the quality of the support provided to them is vital because it is the only personalized individual attention they are receiving. Furthermore, have you considered adding a community aspect to your idea, where students can connect with one another? As a college student myself, I have found that having a community to support me in achieving my goals has been a vital part of my experience, and I think it is important that these working students also have that same support.
Best of luck on your idea! I really love what you are doing!