Thank you DavidBullus and Wayne for your prompt replies, please accept my apologies for my slow response. I should have made clear that I did, for a while, have a progress bar, but that it had disappeared and I couldn't get it back. I now know that the problem was caused by me having to change my Google password some weeks ago, and had neglected to update the tablet that is mostly used as a squeezebox controller. Having updated my Google password on the tablet I now have my progress bar again. I assume that the problem was that my SqueezeCtrl had reverted to non-tablet, or 'phone', mode, and that had removed the progress bar; I have not been using SqueezeCtrl for long and was therefore very easily confused. Anyway it seems that all is well again, and I can add my voice to the thanks to Wayne for a really neat piece of software; I even like the standard background colour, it makes a welcome change.
One question: as I am a user of Erland's Custom Browse and other plugins, can I ask Wayne if the SqueezeCtrl is based on the Squeezebox, or SqueezeCenter, Web Interface? This is because I am trying to alter the track, or 'song', information displayed.