The main thing with making small demo apps while still a student is the data. You need to have a source of data you can use and apply whatever techniques too.

The main thing with making small demo apps while still a student is the data. You need to have a source of data you can use and apply whatever techniques too. Novel business problems are often still unsolved not because making a ML is hard but because getting the data is hard. So for your problems either use easy to get data and apply a new angle on it, or spend some money on mechanical Turk etc to generate the data you need.