Focusing on the sustainability and affordability when using information technology, the mechanism of student-generated questioning (SGQ) and scaffolding for SGQ in reading comprehension tasks were explored within the self-regulated learning framework in this study. We employed a mixed methods design to examine the effects of scaffolding in an SGQ activity on (a) test scores of reading comprehension, (b) the quality of student-generated questions, and (c) participants' experience. Seventy-four 7th graders from a primary school in Kenya participated in this study. They were assigned to one of three groups: (a) SGQ with Scaffolding, (b) SGQ without Scaffolding, and (c) Direct Instruction with Teacher Questioning. As an affordable and sustainable technology solution, low-cost text message-capable mobile phones were employed to support SGQ. Data were collected from the quizzes and posttest of reading comprehension, student surveys, selected teacher/student interviews, and class observation. Statistical analyses showed that SGQ with scaffolding had a positive effect on learning outcomes and the quality of student-generated questions. The analysis of quantitative and qualitative data yielded that SGQ improves reading comprehension levels through the engaged reading with the support of metacognitive guidance.