Mobile eHealth applications have become very popular, not just using mobile phones but also wearables, mobile AR/VR, and increasingly "smart houses" and "smart care" sensing and interaction facilities. However, a large majority of these solutions, despite early promise, suffer from a range of challenges including effort to develop, deploy and maintain; lack of end user acceptance; integration with other health systems; difficulty in tailoring to divergent users; lack of adequate feedback to developers; lack of sustainable adoption; and ultimately lack of success. In this MobileSoft vision paper we characterise these key issues from a Software Engineering perspective and present and discuss some approaches to mitigating them, building on our and others prior work.