MapStore aims to be both a product as well as webgis framework. It is a product in the sense that it can be used with no coding to cover the use case of a standard geoportal, however it is also a framework in the sense that it can be used as starting point to build sophisticated geospatial applications.
MapStore has been designed from the beginning to provide users with a coherent and comprehensive experience across different devices, hence it should automatically adapt to different screen size as shown below.
Check the following presentation for an in-depth look at MapStore or play with the online demo at this link (contact us if you want to receive an account that would allow you to create new maps). If you are impatient, here below we have embedded a nice map served by MapStore 2 for you to play with its embedded version.