I have run tophat as well as XCSoar on the following devices and they both work great: Samsung Galaxy S8+, Samsung Galaxy S7 edge, Samsung Galaxy 6, and Samsung Galaxy Note 4. They all work with no issues. The 8+ has the biggest and brightest screen, but the note 4 has the advantage that you can buy an extra large battery thus extending the battery life to around 16 hours. One thing to note on screen of higher aspect ratio then 16 by 9 they both create small black wedges on the top and bottom of the screen to get the aspect ratio to 16 by 9. Not a huge issue but I would rather the whole screen be used.